Currently the Gamecube controller is used for a variety of functions on Wii. These functions range from playing Gamecube games on Wii, use in select Wii games, and use with downloaded Virtual Console games. Advertising for games such as Super Smash Bros. Brawl and Mario Kart has flaunted the compatibility of the games with many different control schemes, including the GameCube controller.
There is no word of release in other territories at this time, or any mention of a re-release of the wireless Gamecube controller, the Wavebird.