Don't buy it. I bought it because I was curious and I don't see the appeal in the game at all. If it actually controlled well then maybe it could be good, but it doesn't. The game has a large list of faults and the only reason it gets so much praise is because it involves the massacre of of zombies using silly things like wheelchairs. The game will only frustrate you and it's not worth the amount your paying. If you want a zombie game, just get Left 4 Dead or something.
Bet with Conegamer and AussieGecko that the PS3 will have more exclusives in 2011 than the Wii or 360... or something.