NGenres has an interview with Peter Moore from Sega. While the first question is a little light (BTW, he prefers Orange Kool Aid, but has some bad memories of it), the rest of the article is interesting. The big news comes on the second page though.
NG: Does the Sonic Team have development kits for the GameCube yet?
PM: Uh, not that I?m aware of yet. But, if you were to look at a Sega franchise that fits well on the GameCube then, obviously, Sonic is at the top of that list. And from our point of view, we’ll be looking very seriously at what GameCube has to offer, and I know that Yuji Naka, the creator of Sonic, really likes the GameCube hardware. So ultimately, it?s not going to be a shock to anybody if Sonic shows up on GameCube. I think the demographics match, from what I understand, [towards the people that the] GameCube will appeal to. Sonic certainly is a character everybody in the business knows.
While this doesn’t mean that we’ll see a ‘Mario and Sonic’ title any time soon, it does kinda make sense that Sonic is going to the only other console to have a mascot. Sonic Cubed anyone?