Will sell well, even if the game doesn't look really that great (maybe it is).
Concerning the PS3/X360 shares, I think it all depend about MS marketing. They've spend 100 Millions to get exclusivity on specific content (and for this money, I guess this has to be "solid"). If they can push this fact on TV ads, things could be even between the two machines.
PS : KBG, Haze and Noir aren't exclusive ;)