alpha&beta info

Regarding removed resource mana stones:
"Blizzard has confirmed the addition of a second collectable resource into the game - mana stones. Unlike gold, which is harvested from gold mines and is plentiful, mana stones can only be collected by killing NPC "creeps" on the map. There are a small, finite number of mana stones on any given map.
The primary use of these mana stones is to purchase and build new heroes. Blizzard's Rob Pardo mentioned that they might also be used to purchase high end upgrades for heroes and possibly all upgrades, but that detail has not yet been decided. Players will start with enough mana stones to build one hero. This basically forces players to go out and explore the map to find NPC characters to battle with so that more mana stones can be collected."

This mentions ultimate for half-elf ranger:
"Each hero will have an ultimate spell that he can't learn until level 5. Here's a taste of just how good the ultimate spells are: the Human Ranger's ultimate is the Black Arrow, which hits a unit from a distance, quickly reduces the unit's hit point to 1 and then stuns the unit. Pretty useful for killing other heroes, eh?"
Unholy aura was way different and hero we have currently as Death Knight used to be called Anti-Paladin:
For example, the Undead's Anti-Paladin gives out an aura called Unholy Aura, which increases the defense of all your surrounding units. This aura allows your units to survive longer if not indefinitely when carefully controlled throughout the game. You'll be able to tell whether your unit is influenced by an aura if there is a glowing circle beneath him."

This mentions some abilities of human heroes:
"Arch-mage: Heavy caster. His aura is Enlightenment, which increases the rate that your units regenerate mana. The rate of regeneration increases as the Arch Mage's level increases. The spells he can research are Fireball, Blizzard and Mass Teleport. Don't expect the same cheap Blizzard casting cost though. With fewer units in the attack parties, a full power Blizzard spell from Warcraft 2 or Firestorm from Warcraft 1 would be way too powerful. Expect Mass Teleport to be the Arch Mage's ultimate spell. Like the Arbiter's ability in Starcraft, this spell takes a group of units around the Arch Mage and teleports them to a new location.
Paladin: Well rounded stats and anti-Undead specialist. When we visited Blizzard back in April, Calbear and I saw the Paladin cast Divine Intervention on an Orcish hero. The spell made short work of Thrall's poor cousin. We can now guess that Divine Intervention will probably be the Paladin's ultimate spell. The Paladin's Exorcism spell works on all the undead units making him a prime choice for a hero against the undead. The Paladin also has Resurrection which brings any unit back from the dead with 1 hit point.
Ranger: Speedy ranged unit. The Ranger's abilities are Cold Arrow (anti-fire), Flaming Arrow (anti-cold, and possibly anti-undead), and Black Arrow. As we mentioned earlier, the Black Arrow is the Ranger's ultimate ability. It quickly reduces the target's hit points to 1, and then stuns the unit. The Ranger looks insanely powerful right now, which means that Blizzard will probably weaken her in other ways to balance the unit.
Crusader: Team player. The Crusader's special abilities seem to be all auras. Which makes your Crusader the ultimate team player! These auras are Swiftness Aura, Seal of Kings, Seal of Valor, and Seal of Fire. Swiftness increases the speed of all your units. Seal of Kings increases the number of hit points for all nearby units. Seal of Valor increases defense, and Seal of Fire puts a flame shield around all your units. Currently, auras are stackable, which means that your units can benefit from several auras at the same time. Personally, I say recruit three Crusaders, get the three Seals, aura up all your guys, walk into your opponent's town and go "HELLO, I STARTED THESE GANGSTA HITS!"
Mountain King: Heavy Melee. The Mountain King's abilities are Avatar, Thunder Bolt, Thunder Clap, and Giant Slayer. Thunder Bolt and Thunder Clap are direct damage spells. We don't know much about the other abilities. Giant Slayer probably instantly kills a Giant or badly damages them. Out of all the Human heroes, the Mountain King seems like the dullest, but that could change once we learn what the Avatar spell does."
Addendum to above: many spells were designed to be context sensitive, Exorcism became Retribution when cast on an living target, and resurrection functioned as restoration when targeted onto an friendly undead. Divine Intervention mentioned above used to bring in an strong angel to fight by the Paladin's side.
The Archmage had individual Teleportation in addition to mass teleport, Meteor Shower(essentially Rain of Fire renamed), ability named Wizard's Mark and an Time Stop ability.
At Crusader hero Seal of Nobility and Seal of Courage gets upgraded to Seal of Lords/Seal of Kings and Seal of Valor/Seal of Fortitude as points get put in them. The second and third level Seal of Lords/Valor gave ability for spellcasters within range to cast 2th and 3rd level spells without having to research them first.
At some point Mountain King had summon Goldmine as an ultimate ability, and the Orcs had an constructable mineshaft that can be placed anywhere to compensate for it.
Knights could use 'Charge' spell, Rifleman used to have 'Signal Flare', Mortar Team had Demolition ability of Sapper.
what we have currently as Priest used to be Mage+Priest and the other caster of faction being Sorceress.
The Mage had following spells:
Healing(inherent, starts with), Dispell, Inner Fire, Polymorph, Blizzard, Fireball, Flameshield.
Sorceress had following spells:
Slow, Invisibility, Mind Bomb, Summon water elemental
Mind Bomb functioned like an mine, it explodes if any spell is cast within it's radius. Sorceress had no physical attack at all.
Mountain King's look used to change as he levels, his skin turned more and more like stone as he levels. Thunderbolt and Hammer throw had been 2 different skills at some point.
Be alarmed that most of written above was prior to all elemental damage being unified into an single magic dmg type, as its evident with cold/flame arrows description. Half-elf ranger hero also had Evasion as an skill.

Undead didnt use gold at all, their only pseudo-resource was corpses as every unit gets raised out of one. Also at that point this happened neither lumber nor mana stone was in existence yet as resource in wc3.

This mentions some removed abilities of Orcs:
"Peon: The basic resource collector from Warcraft 2.
Grunt: The basic Orc melee unit. His special ability is to go berserk. He'll grow bigger and do more damage (since when did we get into Mario land?). Berserk will wear off when the Grunt's mana runs out.
Orc Raider: Advanced melee unit from Warcraft 1. We didn't get much of a chance to see this bad boy in action.
Witch Doctor: An Orc mage. The Witch Doctor can cast Shadow Pact, a variation on Warcraft 2's beloved Blood Lust spell (which will now lower the defense of a unit while it buffs up the attack), and Evil Eye.
Head Hunter: The Hunter is the Ax thrower from Warcraft 2.
Tauren: The Tauren is a minotaur unit. They are equivalent to the Warcraft 2 Ogre.
Shaman: The shaman is an Orc spellcaster who can cast the spells Chain Lightning, Earthquake, Earthbind, and System Shock. Out of all the Orc units, this guy impressed me the most with his ability to 187 enemy units.
Wyvern Rider: The Wyvern rider is the Orc flying unit. Unlike the dragon of Warcraft 2, the Wyvern Rider must land if it wants to engage in combat against ground units."

This mentions some abilities of Orc heroes, Spirit Walker was an orcish shaman hero not tauren.
Spirit Walker: Counterpart to the Human Paladin. The spells he can learn are Banish (Exorcism for Demons) and Regeneration Aura (the only way for Orcs to recover hit points). He's probably the most important hero in a long-term battle or in a battle with the Burning Legion.
Blade Master: A heavy physical fighter with no aura. Pardo described him as more of a loner. His special abilities include Critical Strike and Mirror Image. Critical Strike looks like Cloud's Braver from Final Fantasy VII. It does triple damage and happens randomly. At higher levels, you increase your chances of performing a critical strike. Mirror Image is like Hallucination from Starcraft. The Blade Master is a great melee unit, but that's about it due to the lack of spells and auras.
Warlord: Relatively well rounded but specializes in strength. His abilities include Death Scream, Command Aura, Howl of Fury, Blood Rage, and Raging Scream. Death Scream damages all the opponent's units in the vicinity of the Warlord when he dies. Perhaps a hero-suicide blitz strategy? Command Aura increases the attack of your units within range of the Warlord. Raging Scream speeds up one of your units, and Howl of Fury directly damages a unit.
Farseer: Flying spell caster. We didn't get to see much of this unit.
Tauren Chieftain: A big time melee unit. His abilities include Reincarnation, Blessings and Warstomp. If the Chieftain has his mana bar is full when he dies, he will come back to life if he has the Reincarnation ability. Warstomp stuns nearby enemies."
Addendum:
Blademaster had an skill named Combat Moves, it used to let him strike lightning fast using martial arts combos.
Wyverns have been projected to be (un-)dead (zombie) drakes instead an species.
Farseer used Lightning Bolt, Farsight and Lightning Storm.
There was one more hero for the horde, simply listed as 'Forest Troll', it was supposed to use an double-edged axe and have the background of fighting for vengeance because destruction of his homeland.
Grunt took more damage during berserk and it had to be timed well as cannot be toggled off before his mana runs out.
Headhunters used to have an skill named Tracking, this allowed them to see the enemy's heat footprint on the land. Meaning: It functioned somewhat like the Sensor tower does in Sc2, aslong an Headhunter is within radius of an enemy unit you get to know position of that enemy unit under the Fog of war.
Shamans had the following spells:
Soul Steal, Lightning Storm, Chain Lightning, Earthquake, System Shock, Blind, Tornado
Witch Doctors had the following spells:
Shadow Pact, Bloodlust, Evil Eye
Shadow Pact spell is used to render friendly units invincible for an short period.
Tauren had an ability named Bull Rush and wield flail/morning star weapon.

Cold Wraith was an hero first, then became their second flight unit, then got cut or rather partly reincorporated into the Lich and partly into Frost Wyrm. Anti-Paladin(what we have currently as Death Knight) used to float around standing on an stormy cloud intead having an skeletal horse mount.
"Cold Wraith: Magic user. Spells include Chill Touch and Life Tap.
Anti Paladin: Paladin's arch nemesis. Expect him to be well rounded in stats like his Human counterpart. His abilities include Unholy Aura and Unholy Armor. Unholy Aura pumps up the defense of all your surrounding troops. Unholy Armor is the upgraded version of Unholy Aura."

Some tidbits about Nightelf hero abilities:
"Daemonhunter: His abilities include Soul Siphon, which drains mana from an enemy and turns it into health for himself, and Flame Blades which can hit opponents for big damage.
Keeper of the Grove: One of its featured spells is Nature's Touch. This spell allows the Keeper to either knock down trees instantly or regrow trees that have been chopped by peasants into stumps (the spell is context sensitive). Nature's Touch brings up a number of interesting strategies. Players might chop into an enemy base, attack, and then retreat back through the hole, with the Keeper sealing the way behind them. Or (assuming you've leveled up the Keeper and the spell to a high enough level) it may be possible for the Keeper to instantly create a hole in a treeline for a Night Elf invasion force to pour in through. Perhaps you could even imprison enemy peasants that have chopped deeply into a tree line by simply regrowing previously chopped trees behind them."
Addendum:
Arch-Druid had 'Sleep' and 'Spore Cloud' abilities. Sleep used to be an Area of effect spell instead single targeted, lasted very short duration and targets wouldnt wake up under no circumstances.
Keeper of the Grove's other spells included 'Barkskin', which allowed it to boost defensive ability of himself, and 'Strangle Fortify'
Daemonhunter had 'Mind Lock' spell, which temporarily disallows one opponent unit from casting any spells, 'Flaming Blades' which functions as close ranged copy of fireball spell, and 'Soul Syphon'.
Moonpriestess used to be airborne and ride an giant owl, she had 'Searing Light' and 'Sunset'.
Nightelven foot soldier was Ent unit. They could morph into buildings or Treants, Ancient protector was named Treant and considered unit rather than building, he still did root in the ground to throw stones from afar though.
Sentinels had one tiny owl on one of their shoulder that can be sent out via 'Directed Scout' ability, the owl functioned like 'Eye of Kilrogg' in Wc2, meaning they were dirigible instead being sent to sit on a tree.
They had an unit named "Assassin", this unit fought at range via throwing shuriken, had the 'Slow Poison', 'Blink' and 'Shadow meld' racial passive.
Dryads had an skill named 'weakness'

Corpse decay was way different:
"So how will corpses be used? To answer that question, Pardo first explained that dead bodies on the ground will exist in two states - fleshy, and skeletal. WarCraft II veterans might remember that dead bodies on the ground decayed over time in a similar way. This time around, the state of the bodies makes a difference. Ghouls, the regular foot soldier of the Undead, will automatically eat any fleshy bodies lying on the ground for a gain in hitpoints. They'll leave skeletal remains behind. Always sticklers for efficiency, the Undead can still utilize those bones. Bring in a Necromancer, and it will automatically use its mana to raise the skeletons up from the ground as skeleton warriors and archers. Does that sound familiar to you Diablo II players? It gets better - Pardo mentioned the likelihood that the Corpse Explosion spell would make an appearance in WarCraft III.
Need more time to bring in your Ghouls and Necromancers from far away before the corpses decay? That's no problem at all - just get a Banshee to sing its Dirge song (all Banshee spells and abilities are songs), and the corpse decay timer will get stopped for a period of time. Aside from the interaction with Banshees, Necromancers, and Ghouls, Pardo mentioned that different Undead spells could affect each of the two corpse types differently."

Apparently Lich had inbuilt orb of frost:
"The Dreadlord's attack is a life draining type that vampirically transfers hitpoints to himself. Pardo also shared with us the four spells of the Lich (each hero gets 3 regular spells and 1 "ultimate" spell). The first one is Disenchant, which is simply an area effect dispel magic. Next up, we have Frost Armor, very similar to the Chilling Armor of the Sorceress in Diablo II. Attackers take cold damage when they strike anything wearing Frost Armor. The Lich's third normal spell is Glacier, an area effect spell that calls a Glacier up out of the ground to strike and chill anything in its radius. Finally, we have the Lich's ultimate ability - summon Frost Wyrm. As a summonable creature, the Frost Wyrm will be redesigned to be large and fearsome indeed, just like the Arch-Druid's Force of Nature. The Lich's regular attack, Frost Shock, damages enemies and slows down their movement speeds."

The hero that got removed early and wouldnt come around again until TFT:
Troll Shadowhunter: This particular hero's spells and abilities are based on "wards" or totems that he carries around on his back. That means his spells are always area effect, but never ranged - he always has to plant his ward at the center of the desired sphere of influence.
His ultimate ability, the Grim Ward, allows the Shadowhunter to reincarnate any dead unit, not necessarily his own! It will resurrect the dead beast to full hit points, which is another difference between this spell and, say, the Human Arch-Mage's Resurrect spell. The drawback of the Grim Ward is that it costs a lot of mana and he must walk right up to the dead body to plant the totem. Still, the tantalizing possibility of stealing someone else's non-hero unit more than makes up for the risk. Other wards include the Null Ward, which is an area effect dispel magic. Simply plant the Null Ward in the middle of the battlefield, and no spell casting can go on in its sphere of influence. Pardo also mentioned the Shadow Ward, which will afford area effect invisibility to your own units and most likely any allied units. More than ever before, allied units in WarCraft III will be able to reap the benefits of spells and auras of their teammates. Pardo explained that this makes team play more enjoyable because of the race combination possibilities.

Some lore behind Death Knight and Cold Wraiths. Note that the Death Knight spoken here is what we currently have as Revenant.
"A few of the surviving Warlocks who were captured alongside Ner'Zhul by the Legion were transformed into physical manifestations of cold. Named Cold Wraiths, they became wicked and cruel. They are filled with the desire to inflict pain and suffering, and they unquestioningly obey their King only, using their newfound powers in his name. Cold Wraiths can fly over the battlefield, casting powerful blasts of freezing cold at their opponents."
The Death Knights replaced the destroyed Warlocks in the Horde, but soon proved to be uncontrollable/unruly and were exiled from the clan. With their master, Ner'zhul, they were captured by the Legion after the war in Draenor. When Ner'zhul became the (Lich) King they refused to worship/bow down to him. As a punishment for this disobedience, Ner'zhul took away most of their magic power and turned them into steel (or maybe put/shackled them into steel (armour)). Now they are just the strongest of the Legion's warriors, without any magical powers whatsoever.

Unholy aura had atleast one more different iteration: It used to reflect damage inflicted on friendly units back to attacker.
Dreadlord had Dark Summoning as an ultimate at some point, which remaint in the editor and even has fields filled up if you untick it being an item ability.

Shade unit had ability to assume form of any enemy unit, becoming able to mimic it.
They had creature named "Dredge", but nothing is known about it.

Undead's first hero was Necromancer, they would always start with one, he built the base and produced(summoned) all of the undead troops, he had the following spells:
Raise Dead, Summon Structures, Creeping Plague, Winds of Woe, Haunting, Ashes to Ashes, Drain Mana
Drain Mana was used to sacrifice an living unit to gain mana.
Haunting did get cast on undead buildings to reinforce and allowing attack so they can protect themselves.
To tech up the Necromancer would have to cast 'global spells' that also benefited the entire undead race.

Crypt Fiend was an hero too, it had upper body of female human, lower body of spider. Striked at melee using legs, wielded an bow at range and she used to summon spiders, bugs and reptiles(!) ,spits webs and had an skill named 'Arachnid Control'.