Shigeru Miyamoto confirms not only that Zelda is in development for Gamecube, but that the footage from SpaceWorld was actual gameplay footage!
Nintendo's Shigeru Miyamoto has confirmed the development of Legend of Zelda for GameCube, he also confirmed that the GameCube Zelda video from last year's Nintendo Space World were [sic] the actual gameplay footage. The GameCube version of Zelda will be directed by Mitsihiro Takano, the project director of Legend of Zelda: Majora's Mask for N64.