Some of these are a little far-fetched, but whatever
1. Mewtwo will return.
2. Dr. Mario will return as an alternate costume, accompanying other alts including DK Jr., Fusion Samus and Biker Wario.
3. Square Enix and Capcom will be represented in some form.
4. Due to legal disputes or marketing restrictions, one of the current third-party IPs represented will be cut.
5. Miis will be playable due to fan demand.
6. A character from a brand new or revived IP that we have not been exposed to as of October 27, 2011.
7. Star Fox, Yoshi, Pikmin, Mother and Kirby are set. No new characters.
8. Wario will get a newcomer from WarioWare.
9. Marth, Captain Falcon and Ness will become starter characters.
10. The roster will be smaller vanilla, though with DLC it expands slightly.
11. At least three of these: K. Rool, Saki, Ridley, Tingle, Toad, Little Mac, Isaac, Samurai Goroh, Lyn, Zoroark, Dixie Kong will appear as newcomers.
12. Kid Icarus gets a newcomer.
13. 3DS and WiiU will get platform-exclusive characters.
14. Pokemon Trainer gets a changed party.
15. There will be a newcomer that surprises the majority of fans.