The Legend of Zelda: Mask of Majula
The Legend of Zelda: Mask of Majula (formerly Zelda Gaiden) will be the semi-sequel to The Legend of Zelda: Ocarina of Time. Nintendo has been careful not to give away too much information, but from what has been released we know that it is due sometime around April 27, 2000, it requires the expansion pack, and is aimed at keeping Zelda fans interested until the release of the Dolphin Zelda. The Dolphin game in the series won't be here for five years, so Zelda: MOM will be released to keep Zelda fans occupied until the next one. So far the plot is this: afew months after Ocarina of Time, Link is in the woods and a stranger with a mask appears and steals Epona. Link follows this person into an alternate universe. This universe resembles Hyrule, and the people look like the people from Link's world. The moon of this planet is falling towards them and Link must find the masked person to return to his homeworld. The masks of Zelda: MOM have a slightly different purpose here, instead of the being regular masks, they transform your entire body. Different masks allow you to do different things. Goron mask: Allows you to roll at high speads. Zora mask: Allows you to swim with acuracy. Deku Shrub mask: Allows you to spit rocks and use certain flower petals to fly. Bunny mask: One can only guess <gulp.> Along with these abilites, each creature has it's own instrument. Goron has an impressive set of bongos, the Zora has an awesome looking fish scale guitar dude, and the Deku Shrub pulls out a set of horns. Another different thing about Zelda MOM is the sundail at the bottom of the screen. Aparently, if you take too long to beat the game, you lose. This game promises to have slight improvements over Zelda: Ocarina of Time, and the controls seem the same. From what has been released, this seems like a very promising semi-sequel.

Thanks to RedLink for this info.