Yup, have got myself a copy 3 days ago.
First: The air units aren\'t a big change to the overall gameplay. But I think thats a good point. They can \"just\" fly over every terrain. Abilities of these flyers are different for any faction.
Dark Eldar: I still think the suck at how they look, but I have to admit they are a force to count on in future...They are fast and hit hard. All of their buildings built for themselves...Oh and did I mention that they can do magic all over the map (souls must be harvested for cost)?
Sisters: Haven\'t played with them yet. But the penitent engine (2 buildable) are hell of a weapon...fear them or get burned to the ground.
They use holy force for some special abilities, but can say too much about them so far.
SO if you like DOW. Its a must buy! Allthough not so big changes, but the game was perfect before. Starcraft sucks!