This. Wreck it Ralph would be awesome and if they could create something like kingdom of hearts with it, then the game will surely be a great hit! Hopefully they will because the idea is great!Wreck-It Ralph would definitely be my first choice since I loved that movie so much and think there'd be loads of opportunities for meta-humor and even some more crossover things. I mean, who knows if the movie will have a sequel by then that takes place in home console game worlds, which has been rumored. So in that case they could definitely show the ACTUAL game worlds from the Final Fantasy characters that have shown up before, all as a part of Wreck-It Ralph's setting. They could even go one step beyond and have BOTH the original game versions and the Kingdom Hearts redesigns from those games in the same game and deal with that in a humorous way.
While I am not too fond of the movies, I still think Cars, if done right, could be fun. Just like how the Lion King world did in KH2, a Cars world could definitely spice up the gameplay a little bit. And seeing how there's gonna be this Planes movie, based in the same world, I'd think Disney would approve of this as well.
I definitely wouldn't mind some Marvel, Star Wars or other LucasArts worlds, either.