I played this map long enough to determine that I don't think much of it as it stands now. There are a great deal of things to be improved, and the following is a review of some such things.
First off, the map size is pretty large considering how basic the map's principle elements are. I recommend cutting-down on some of the custom models just to conserve some space. This is directed primarily at the hero models. Speaking of the heroes, are three of them really necessary for each force? One per player should be enough, methinks. What you could do is make the map playable by eight players and have two players per force, so each force could have two heroes played by different players... I dunno, it's your map.
If one of the player-spots isn't being occupied, spawns for the vacant force continue, and their main building still stands too. That shouldn't happen; continual unit spawn that aren't even controlled is a useless waste... remove that.
Terrain could have been done much better. Doodads were certainly an endangered species in that map. Don't hesitate to zest-up the environment... it really would add to the game-play if the lands looked good enough to battle for. As a side-note, I liked the placement of the water. Another point about terrain: I'm not sure if it was your intention to hide all the bases, but some bases were extremely difficult to find (like the Undead), while others (like the Dwarves) were begging to be infiltrated. Try to balance that out. I also don't think that the Humans and Blood Elves should be neighboring each-other. If you really insist on having them allied as your story dictates, at least have them separated as all the other bases are.
It's a start, and this critique could continue a little further, but I think you have enough to mull-over for now. Good luck working on it further, if you indeed to plan to.