i have had all 3 most of the time (even loved my dreamcast)
last gen it was:
xbox for halo
ps2 for final fantasy
gamecube for zelda
gears of wars certainly looks awesome, and i'm sure square will have a solid FF for ps3, but frankly the price of admission for ps3 is ridiculous for 1 game (even if it is a final fantasy title), and while there are some other decent "exclusives", something similar and almost as good will be on other consoles (not to mention bluray may turn into another betamax).
looks like this round may just be limted to wii (zelda) and 360 (gears of war, the next halo - altho halo 3, halo wars, halo movie, unnamed Peter Jackson halo project.... halo overload?) for me...
in the beginning, ps2 won out due to hype (the launch titles sucked, as did the gfx in the beginning), backward compatibility, and fan loyalty carried over from ps1. not sure those things will work for sony this time..