I don't like sequels to FF games. Square should leave that to their other franchises, like Kingdom Hearts (which needs a prequel, by the way).
I'm pretty sure KH3 is a sequal. ^_^
I like the idea of the games story ending and me saying "wow...." instead of it ending with a cliffhanger and me saying "dammit, now i gotta pay another $50 to see how it turns out"