FF1-6, 9=Amano
FF7,8,10,10-2=Nomura

Kingdom Hearts=Nomura

THUSly: I don't count on seeing any character from any FF other than 7,8 and 10.
We do know, definitely, that Auron's in it, b/c he's in the trailer lookin bad-azz.

If something happened to make nomura want to use some of amano's chars, I'd want to see BigOgreUmaro, Relm, and Strago from FFVI; and Rydia from FFIV; and yes, Vivi.