The Following was taken from a Press Release from Nintendo:

Our development team has decided to take extra time to add some incredible new elements to The Legend of Zelda: Twilight Princess. As a result, the game will now launch in 2006 globally. We recognize there may be some disappointed fans, however we firmly believe this additional time will result in a much more enjoyable gaming experience. GameCube fans will have a variety of Nintendo games to choose from this Christmas, including Mario Smash Football, Battalion Wars, Fire Emblem: Path of Radiance and Pokmon XD: Gale of Darkness.

Dissapointing