According to the latest issue of Japanese gaming magazine Famitsu, Nintendo will indeed debut The Legend of Zelda: The Wind Waker 2 for the GameCube at the upcoming E3 show in Los Angeles in a few weeks from now.
Whether or not this actually happens remains to be seen, but if it is, it's highly unlikely that the game will be playable -- instead, it's more likely that a small portion of video footage will be shown at the Nintendo E3 press conference.
GameSpy will of course bring you any updates on this story as it happens.