On www.gamespot.com I was sbrowsing thrue the Gamecube section and I saw somthing that said: Sonic adventure(Workingtitle). is there going to be a Sonic adventure 3? or a Sonic adventure gamecube version?
Sonic Adventure 1 is the only "Adventure" title coming out, and yes it's on GCN. An all-new 3D Sonic game in the far-away future. Mega Collection, SA1, and Sonic Advance 2 are the only things at the moment.

~ SA Tails