GT5, maybe; nothing else. FFXIII, in particular, has no chance; not even FFVII managed that feat, and (other than FFX) sales have been going down ever since then.

How have sales gone down for Final Fantasy? FFXI did terrible as a MMO in sales, but FFXII did about 5 million on the PS2 alone. I'm almost sure that FFXIII won't make 10 million, even if it was exclusive like the last ones (except for FFXI on the 360), because the most popular one, the seventh, didn't even crack ten million at all. It's split on the 360 and PS3, so probably not even ten million combined.

Exactly. Each post-FF7 game has sold less than the one before it, with the exception of FFX. Although FFXII did about 5 million on the PS2, it's important to keep in mind that the FF fanbase has been split this generation: some stayed with the PS3, some jumped to the 360, and a few jumped to the Wii (which isn't currently known to be getting FFXIII at all, but that will have its own effect on sales). Even if we assume a similar blip as happened with FFX, where the first game of the gen sells about 1.5x as much as the game before it, that comes out to about 7.5 million split between the PS3 and 360. Assuming a roughly even split worldwide, that doesn't crack the 4-million mark on either console.

Gran Turismo 5 is probably the only game that can do it, until GT6 ;)

Considering Sony is attempting a 10 year console lifecycle with the Playstation 3 I'm willing to bet Gran Turismo 6 will break 10million when it most probably gets released in 2015 and when the Playstation 3 userbase is higher... Or pehaps everybody will do the logical thing and be playing on a much more advanced and more powerful console by then.

The Playstation 1 and 2 lasted so long because of their cheap price and outstanding games libary, the Playstation 3 doesn't match that criteria so good.

I doubt the PS3 will survive the ten year plan Sony has for it. But like another poster on this thread said, ten years is a long time, so a game could reach ten million in that time. But the PS4 should be out by then, and it will steal most of it's sales by then.