I really loved the demo. It's really smooth, it feels like real basketball, the way Lebron and D Wade move, the way Dirk shoots... The little details too, court spacing, player moves. If you don't like this, you probably don't like basketball, it's really fantastic. I can't imagine how incredible it will be with playcalling, my player mode and association...
It looks better than 2k11 too, on ps3 at least, since there was a lot of aliasing in 2k11 PS3.
Congrats to 2k, I absolutely loved 2k11 and I can't wait for 2k12 now... October can't come soon enough.
My only worry is about some moves from the post which look near unstoppable with Dirk, you know when you fade to the side and shoot, from the post. Looks very hard to stop. It's a minor complaint, though. I hardly can find anything negative.
Overall, it rocks.