Pretty sure that the developers stated that not all the FF games are going to have a new playable character. Also, there's strong rumors that Vaan will be in the game as a representative for XII, though I still have hopes for Basch...and also Auron. He seems like he's a fan favorite, so there's quite a good chance that he'll make it in, though I'm still thinking that Yuna could just as easily take that spot.

Eh... I suppose it's all just speculation until there's official word.