None of them will flop. A flop means that it gets, say, less than 200k WW first week.
As for underperforming, Killzone 2 will definitely not underperform, because Sony will not let it. You can't compare it to LBP, because that's aimed at the wrong audience, you can't compare it to R2, because Sony didn't spend upwards of 20 million bucks developing Resistance 2, they basically told Insomniac to make a sequel, maybe helped them along a little, and gave them less than two years to do it (while Killzone 2 has had 4 years). 4.5 million.
Gran Turismo 5 will not underperform, because it's Gran Turismo. It doesn't NEED advertising. 8 million.
God of War III? No way. God of War III will sell incredibly well, because it's mindless gory violence in HIGH DEFINITION. 4 million.
Heavy Rain? Unfortunately, it just might. It doesn't seem the FPS junky's cup of tea, really. It will be amazing, and I will buy it, but unless Sony advertises the hell out of it, it probably won't sell very well. No
te if this breaks a million first week I will deny ever saying this. For now, I predict 2 million.
inFamous? Probably. Nobody really knows what it is, it'll score high 8s, get respectable sales (ala Uncharted), but not be a runaway success. 2 million.
Uncharted 2? People actually know it's good now. People actually own PS3s now. This will sell very well, upwards of 3 million.
All numbers are for a year after release.
(Former) Lead Moderator and (Eternal) VGC Detective 
