Why can't MGS, FF, GT sell as much on PS3 as they did on PS2??

[Bodhesatva]

I think MGS4 and FF can, more or less. A lot of it is dependant on how "hardcore" the userbase is. Mario Sunshine and Mario Kart: DD and SSBM all sold very well on the Gamecube, despite a much smaller userbase than either than N64 or the Wii. This is because these are very traditional franchises with a very loyal following.

I think the same will apply to FF and seems to be applying to MGS4: the fans of these franchises will follow them anywhere, no matter what the install base, no matter what the cost. They are very, very loyal. Gran Turismo I personally believe is still hardcore, but a bit more casual than the other two -- therefore I believe it will see a noticable but not terrible drop off, something in the 25% range.

Other similar franchises: Smash Bros, Halo.