You know, I expect the PS3 to have the least amount of new mainline FF games and PS4 to have most in FF console history.
So 4 or more? I really doubt SE has that capacity...they'd pretty much need to release a new mainline FF every other year or so.
I wonder if SE will even make a new mainline FF MMO btw. FF XI came out in 2002 and FF XIV came out 2010. They shouldn't even bother till the very end of next gen or the beginning of the one after.