I played the demo for a little bit on Xbox. The graphics are really amazing. The fighters look just like they do in real life. The stand up in the game is really good. You can control what types of punches you want to throw.
But the ground game isn't to good. You can just block their moves and hit one button to move your self.
I'll have to play it some more before I decide to pay 60 bucks for a game.
He's a great review from bloody elbow on it.
http://www.bloodyelbow.com/2010/9/28/1717946/ea-mma-video-game-demo-review