This new rumor has been spawned by comments of a 1UP staffer in their podcast. At 55 minutes the following takes place:
So at this point its just a rumor, but if true I know Ill be selling my XBOX360 for sure as this and Dead Rising were the only reasons I bought it. If it holds true, I really cant see much point in keeping it just for Dead Rising.1up staffer #1:After wagering the Microsoft and THQ have done a deal for Smackdown vs Raw 2007 next-gen exclusivity, which actually makes a bit of sense) "Right now a lot of the games you think are multi-platform next-gen games coming out on both PS3, 360 and Wii are going to end up on only one console... this fall. Get ready."
1up staffer #2: "So... well... what do you know?"
1up staffer #1: "I don't know a lot and I don't know if its going to be announced and this is just pure speculation from me based on intelligence I've gathered... (background giggles)... TGS... Resident Evil 5 PS3 exclusive."
1up staffer #3: "Yeah, I can see that."
Credit for this goes to Jesus2006 at the Beyond3D forums.