Earlier today Nintendo Now posted an image from Nintendos E3 display for Sonic Gems Collection for the Nintendo GameCube, which sports the controller layouts for Sonic the Fighters and Sonic CD. Details at the moment are at a bare minimum, although this is definite solid evidence that these two games will indeed be appearing in Sonic Gems Collection and playable at E3.
The photo can be found under the media links. Stay with SONIC NEWS for more E3 2005 updates.