To be honest, Sonic games haven't been THAT bad on the "terrible" cast mates lately. Unleashed had a few but kept it to a minimum, S4 had Sonic and Robotnik(fuck the name "Eggman", sounds stupid), and Sonic Colors had only Sonic, Tails, Robotnik, and Robotnik's henchmen. Sega's starting to get the idea that we don't NEED most of those pointless characters.
See, to me Unleashed was one of the ultimate offenders, because Chip was terrible/unfunny, and the Werehog was essentially turning Sonic into a shitty friend himself, which is absolute heresy. Not to mention that I hated the ugly, ugly world people that were designed with inspiration from awful Bible cartoons. I do agree that since then, Sega's become far smarter in that department.
If it were up to me, though, the only remaining friends would be Tails and Knuckles, while the rest would be thrown in a gigantic Egg Meat-Grinder. (I'd exempt the Chaotix guys as I fucking love the 32X game, but even they have been tainted by Heroes.)
Aaaanyway, I'm highly anticipating this game. I loved what I played of the DS Colors, and the Wii version looks goddamn amazing; my main fear is that the Classic Sonic portions will be entirely recycled levels, but the potential of classic themed versions of newer levels like those from the Adventure games sounds way too cool to pass up.