Keep in mind that the PS3 has nowhere near the userbase that the PS2 had when trying to figure out how many copies a game will sell.
I'm not saying that GT5 will flop or anything, but I don't see 10+million sales for it either. Remember also that when Prologue was released there really wasn't a ton of great PS3 games on the shelf and Prologue was always priced lower than a full release.







