Just after the end of E3 2004's first day, Nintendo held a roundtable discussion so that the press could hear from the director of Wind Waker and Link's new adventure, Eiji Aonuma. During the event, Aonuma confirmed that the new Legend of Zelda game--unveiled at Nintendo's pre-E3 press conference--is currently scheduled for release in 2005.
Additionally, this game is the same one that Aonuma referred to as "The Wind Waker 2" back at the Game Developers Conference in March. The game won't be called The Wind Waker 2 when it's completed, and it won't be a sequel to the last GameCube Zelda game.
Link is said to be a teenager in this new adventure, and his horse--not confirmed to be Epona--is said to be a prominent element of the gameplay. We'll have more on The Legend of Zelda as it becomes available.