btw, wheres this SC campaign that Pyrodactil speaks of?
of course in the SC
i just noticed that things in cinematics look different from things in game (not because the ones on the cinematics look 3d

)
first take a look at the hydra of the original zerg campaign. It's a cinematic hydra, it has no spine like things on it's tail.
I think the reason why cinematic units show difference to units in-game is the following: the ones who made cinematics had no contact with the other ones who made the unit sprites, or just disagreed each other's work.
BTW i took a look on the PR models. They look really good, and especially really PRECISE. I hope the animations will be also so precise.
If they'll ever complete what they do i'll probably remake the original SC campaign from other aspects.
For example: show a bit more about the battle on Tarsonis (how the protoss battled the zerg here, and what the terrans did on the ravaged planet), the battle on Char (how the terrans arrived, what did they do after they were beaten by the zerg here, ad how Raynor met with Tassadar, and of course what Kerrigan did after the swarm left to aiur).. and so on