I seriously doubt a handful of sequels are going to guarantee PS3 sales going through the roof, definitely not to the kind of levels that the Wii experiences. Every title listed there appeals to a narrow demographic of gamer, and while they will sell well, I don't see any of them being true "system sellers".
FF13 has a lot of stigmata working against it with pre-FF11 fans who don't like the shift the series has taken; I know I for one am not looking forward to it, in spite of having gotten all but FF11 of the previous mainstay FF games. Killzone 2 has plenty of competition as it is and had an underwhelming prequel; it's going to have to sell on hype alone. Gran Turismo 5 is largely going to appeal to the graphics-lovers and racing fans (which make up decidedly less than a majority of the gaming market, even combined); unless it gets bundled like GT4 did, I don't see it getting the kind of sales that even FF13 will. Little Big Planet is so very niche, I suspect another "Eye Toy" debacle may occur, ie. massive hype and low sales. MGS4 is definitely hyped, but so delayed that it's probably lost more than a few sales (definitely to the ones who are hoping on a 360 version).
Of all those listed, MGS4 has the most potential to move systems, and it's got the "wait to see if there's a 360 version announced" crowd working against it. I could be completely wrong on all of these, of course. But evidence against them being the system sellers people hope they will be is there.
Sky Render - Sanity is for the weak.
