Sora is probably the most hyped character I've personally seen around the internet when it comes to Smash, and it's possible that he gets in. People are skeptical because of Disney, but lately, it seems that Disney is more lax when it comes to games and their properties (willing to bet a LARGE part of this is because of the financial and critical success of KH3). So, it would be a huge deal if he's the last one.
However, Square has two reps in the game now, and even though Sora is a Disney rep... It's iffy. Plus you know how people are going to complain about "too many swordsmen" in the game. So who knows.
I would love if Crash Bandicoot was chosen too, that would be really fun.