Posted this in Official Character thread, but with so much Bayonetta Talk, was omitted.
Think this can work for Snake's inclusion (eventually..if not in 3DS)
With Bowser Jr and Duck Hunt left to be revealed, I don't think any of the remaining unlockables will be new characters.
Sorry Ridley, Krool and Dixie. Maybe for WiiU or DLC.
Before Robin (Lucina) and Shulk were revealed, I am pretty sure Sakurai stated we are nearing "the bottom of the barrel" with reveal trailers. If you throw three more characters in, that defeats the whole purpose of saying it to begin with.
Think that most of the New Characters will have their reveal trailers in the game (akin to Brawl with third parties) and that's part of the reason they get those trailers, to make them special. Clones are simply tagged in other trailers (Dark Pit, Lucina).
If we are looking at characters not listed on the leaked roster, we have about a maximum of 5 slots (if Miis replace Random), should look at these guys: Lucas, Wolf, Mewtwo, Snake, Ice Climbers.
If the Roster is completely full and you take into account that Gematsu was early information, it is a good probablility that we will get those 5 (or swap a Rhtym Heaven rep in for Mewtwo or Lucas).