Well, it can't be worse than Sonic Battle. Or Sonic X360, although knowing Bioware it'll be just as buggy.
After thinking about it, I think the Sonic RPG could work. Sonic's shitty friends could actually be useful in an RPG instead of being a hindrance in a 3D Sonic platformer (StH2006 excluded, since Sonic was a hindrance in that one). And the generally retarded plot that you see in modern Sonic games would fit in a RPG; I mean, people bought into FFVII for ****'s sake.
Since Bioware are making it, it at least should play alright. Hell, it'll probably be the best RPG from Sega since SoA. I hope this means we get Skies of Arcadia 2 or Phantasy Star V from Bioware somewhere down the track. They'd at least do a better job with SoA than Overworks did.