Cruising around the Wii game pages on Nintendo.com, we noticed something a little odd in the listed "Extra Game Features" for the Wii's Genesis Virtual Console games. While other virtual console games all list support for the GameCube controller (and the Wii remote in the case of NES and TurboGrafx-16 games) all the Genesis game pages insist that you "use the Classic Controller to play this game." This contradicts an interview with CVG where Nintendo said "all virtual console games can be played using the Classic Controller or Nintendo GameCube pads," but seems in line with a note in the Wii manual that says "some Virtual Console games can only be played with a Classic Controller."
The Genesis seems an odd system to single out for a lack of GameCube controller support, since the system's three buttons would map relatively easily to the GameCube's B, A and X buttons. Personally, we don't relish the idea of spending $40 for two classic controllers just to get some multiplayer Toejam and Earl action going, but we will if we must.
We've contacted Nintendo for confirmation on this matter and will update as soon as they get back to us.
[Update 1: Since launch it has become apparent that Genesis games do work with the Gamecube controller and occasionally with the Wii remote as well. The Nintendo game info. pages have been updated with this information.]
[Thanks to the commenters on this post for pointing us to this story]