MGS 4 and FFXIII are the only system sellers for ps3 I think. Is killzone that well known, how did the first killzone do, good graphics=sells? Will killzone make xbox users in america buy a ps3 to play a fps where xbox seems to be the king in that genre. Splinter Cell games don't have amazing sells. GT5 may sell systems, it has a good chance but not a sure game, I don't think racing games sell that many systems. The rest aren't really that hugely known.
GTA4 will help the xbox more then help the ps3, why would americans get ps3 to play gta4 where xbox has it with more content. In other areas I do see it helping the ps3 a lot but not in america. The rest of xbox games don't seem that well known, fable 1 didn't have any huge sells, not the kind of sells to sell systems.
Wii with very low number of games, but all those games will sell millions. Excluding GTA4 for xbox, those 3 wii games will sell more then the rest of those xbox games combined and close to the sells of those ps3 games as well. One of the things that influenced me to think poorly on what certain games can do is how halo 3 sold systems, wii is ahead by millions now...
Not saying all those games are horrible, but many of them aren't system sellers, they will sell good (be up in the millions) but not push a huge rush of customers to buy systems. Also why are people doubting wii fit will sell well, one huge reason for the craze about wii is the exercise nature of it, of course wii fit will sell very good.