Although I do agree that Mickey has mainly been on Nintendo, Solid Snake made it to SSBB although people remember him mainly from his PS games (No one remembers Metal Gear on GBC). This is because Konami has no ties to either console just as Square Enix has no ties to Playstation. Kingdom Hearts has been on Playstation 4 times, the same amount of times its been on a Nintendo console. Epic Mickey has a sequel that will be on PS3, just fyi.
Last thing I'll say about this, I really think KH should get the hell away from the god damn Nintendo consoles like the DS and just make a game on the PS3 already. Do they even know how many fans want a PS3 game already? I don't think they know. This is just as bad as waiting for HL3, except without shitty little DS games. Honestly the only thing I enjoy on Nintendo portable devices are the pokemon games. I'm sorry, I just had to let that one out.
This is the last I will say on this topic as well.. The eproducers and designers will pick the characters not us so technically as far as we know Mickey has just as good of a chance as someone like cole McGrath oR Goku(hate to say it but Goku still has a chance of getting in..) and that leads me to say "truce".. I don't want to argue..
I feel like Cole would have a bigger chance than the 3 you listed, because he IS a Playstation All-Star, inFamous is a Playstation Exclusive and was made by the same creators of Sly Cooper, who is also in the game.
I had another idea:
How about a PAS: BR T-Shirt/Hat for sackboy for hardest mode completion? Or perhaps Yellowhead?Pata-pata-pata-pon
Yes! I love the idea of Yellohead. Added!