No, that's the whole character list right now.
Also, as awesome as a Castlevania character would be, it's Konami, isn't it? They already got Snake in, if Nintendo lets them put in two characters and doesn't give Sega one *cough*sonic*cough* than that wouldn't be smart.
Also, if you've played Sonic Battle on the GBA, you could use the hedgehog something like that in Brawl. Look at how fast C.Falcon is; I think that's enough for Sonic.