Depends how many exclusives Xbox has next gen. They have 2 big/main exclusives a year this gen (or atleast that's how it's been for like the past 3 years), so whenever one comes out they are so starved for a new exclusive to play that everyone buys it hence a shitty game like Halo Reach getting 8 or 9 million sales. Whereas the PS3 ( and Wii to some extent) has exclusives coming out every couple of months so they aren't in as high of demand since the gamers are still playing LBP2 by the time KZ3 comes out and this causes less people to buy it. Also when given a million awesome exclusives it means they won't have enough money to buy all of them so they only choose a few of them to buy per year and pick up the older ones as well as new ones when they get the money. So if the Xbox 360 has less exclusives then Sony or Nintendo or Apple if they make a console next gen, then they will inveitable sell more based on demand and brand recognition.
