I voted maybe.
It will come down to the games. If Sony can market their games and advertise them properly, people will buy them and people that don't have PS3's will buy one. Really, it's going to come down to the software and their ability to deliver. If their sequels (God of War 3, killzone 3, resistance 3, infamous 2) aren't pushing the limits of the system and they don't come up with any new franchises that really blow peoples minds, than no, PS3 will NOT take over the sales position Xbox holds.