In the next week people are expecting an announcement about game designer Warren Spector's next game for Disney. Everyone is expecting it to be Disney Epic Mickey 2, but so far no one can say that it definitely, positively, is. However, in a recent interview with GamesIndustry, the interviewer asked Spector what he would do differently for a hypothetical sequel to Epic Mickey.
His reply suggests that, if he is about to announce Epic Mickey 2, he is to announce as well that he's making exactly the changes people want. He says in a sequel he would work to improve the oft-criticized camera (although he continues to insist that people don't appreciate the camera work of the first game). He says all the dialog would be full voice instead of text (he explains that the text approach was both because it was common in similar games like those of the Legend of Zelda series and because Oswald the Lucky rabbit was a silent film star). He says that, based on feedback he's gotten, he would put the game out for more platforms and that he would add co-op so parents could play it with their kids.
Spector also mentioned that the unnamed game he is currently working on has 700 people working on it, and that Epic Mickey was made with a team of 180. But it's hard to say how much of that increase would be because his next game will be more epic and how much is the result of working on multiple platforms.
Rumors suggest that the Mickey sequel would come out this fall for the Wii, PS3 and 360. There's also a very insubstantial rumor that the developers are working on a Wii U version or a version with Wii U compatibility of some sort. We'll know for sure very soon.