I just don't see it happening. According to this site, Japan has always been the single largest market for Final Fantasy games as far back as VII (I didn't check before that). Square would stand to lose millions in potential sales by not releasing on a console with a decent base in Japan.
Granted, the PS3 isn't in much better shape over there, but, if the game is going to change platforms, it only makes sense to go all the way and put it on the Wii. That's the only way they can match the sales of their older games in Japan, and it's not exactly weak in the US either.







