As much I would love to have Sora I don't see it happening because of Disney. He wouldn't even get to have Goofy or Donald in his moveset which is fine I suppose.
But he's really no longer a PlayStation character in my eyes because Square Enix are a bunch of **bleep** putting all of the **bleep** spinoffs on the Nintendo handhelds except for Birth By Sleep.
I would love to have Roxas more than Sora. One of his specials could be where he dual wields Oblivion and Oathkeeper. Another he could call in Xion or Axel. Axel could throw out his weapons and hit the people in front of him. Or something that would have to do with fire?
Or at-least if it comes down to it Roxas could be a bonus costume to Sora.