There has been a lot of talk recently on one specific piece of intel. The sequel to Sonic Adventure. Sega of Japan all but confirmed the game recently, and now the gaming grapevine indicates that we may be seeing it sooner than we thought.
It seems that Sonic Team has already begun development on Sonic Adventure 2 -- coniciding in fact with their continued work on Phantasy Star Online. And there are rumblings in Asia that the game could see its release in Japan as soon as next year! We'll keep youposted on anymore new info that we find out.
Source: Sega X