I really believe that GTA4 will really mark the shift of gaming into the HD era for PS3 and 360. Of course, the PS3 will get the bigger boost since there are many GTA fans who have a PS2, and only know of playing GTA on the PS2 and will move naturally to the PS3. Even with the extra content, it doesn't sway me into purchasing it for the 360 over the PS3 and I will buy it for the PS3. The GTA series has always been a huge game with tons of content, and I really don't see a need to add more content to a already huge open game like that.
So, look at GTA4 to boost sales for both consoles, moreso on the PS3 as they have been outselling the 360 in recent weeks with a arguably weaker game library then the 360. The recent Live issues as well as the RRoD will sway more buyers of the systems then extra content. I'd expect that combined, GTA4 will sell 12+ million games within a years time.
My pokemon brings all the nerds to the yard. And they're like, "You wanna trade cards?" Damn right, I wanna trade cards. I'll trade this, but not my charizard.
