Well chances are there won't be any third Dissidia, at least not in the same form. I'd rather have another main series installment than another one of the countless spinoffs.

Don't get me wrong, I liked Dissidia a lot (took me 300+ hours to get all accomplishments) and I'm definitely buying Duodecim. It's just that this game has so crappy story and takes so much time - it's so addictive! If we were to get third Dissidia, I want a decent story (not many chances here) and some serious RPG elements.