This honestly makes me sad, 'cause these people going SO fucking hard (no pun intended) for Tifa, is just going to end up FORCING it to be Tifa and completely destroy the chance of any other, better FF characters making it into the game. Not just because it's unlikely any single IP will get more than one slot, but because you KNOW all these people are going to throw the biggest fucking hissy fit under the Sun if it's ANYBODY BUT TIFA (except maybe Cloud).
As I said before, I'm hoping for it to be Clive while acknowledging that it's more than likely going to be Tifa.
For non-Final Fantasy characters, my biggest shot in the dark would be Chris Redfield or Albert Wesker, Capcom IS making a Resident Evil 5 Remake at the moment after all, might as well get something cool out of that (as long as they use the OG designs).