I've said this before, but I'm guessing they're just gonna cross off every character except one and give us a new set of characters each day. There's just too many characters in that picture that couldn't possibly be playable and/or are obvious jokes (even SonicTeam's not that bad). The only ones in there that I could possibly see being playable (aside from Sonic) are Amy, Shadow, and -maybe- Tikal (maybe Shade as well, I don't know anything about her). I'd also be surprised if Tails and Knuckles didn't make the cut, their absence just cements this to me more. So that would suggest that none of the characters listed here are in the game except Sonic.
Of course, there's the chance that they're even dumber than I could possibly imagine and the final roster is Big, Froggy, Mr. Needlemouse, and Chip. But I hope it's not that bad. Guess we'll know whether I'm right tomorrow.