The sequel to the first Dissidia is due out this spring, woot! A bunch of new characters are coming in. I'll showcase all the scans here. Also in the game will be Tifa and Kain Highwind, but I need to dig up those scans yet.
The game also has a new assist system and a "Create your own adventure" mode, not sure how that's gonna work out yet. Also, the game will have an actual world map, so say goodbye to the Destiny Board (though I imagine that may come back in "Create Your Own Adevtnure...if I were Square-Enix, that's how I'd do it lol)
The recently confirmed Summoner Yuna, will have the ability to call summons out onto the battlefield:
Laguna Loire (I was so stoked when I first saw this) from Final Fantasy VIII:
Squall and Ultimecia's new alt costumes: