Nintendo revealed an entirely unannounced game in The Legend of Zelda series, called The Legend of Zelda Triforce Heroes for the 3DS.
Triforce Heroes will have a strong focus on cooperative multiplayer, in contrast to previous Zelda multiplayer games. While those games were more competitive, Triforce Heroes will be more about working together to explore, solve puzzles, and defeating enemies.
Triforce Heroes also incorporates switching between 3D and 3D forms, a mechanic introduced from Link Between Two Worlds. This gameplay element is brought together with team gameplay via the new Totem mechanic. You and two players can form a totem by standing on top of each other so you can simultaneously switch to 2D/3D and back. Four players seemed impractical, so Nintendo has set a maximum of three players to form a totem, and to play at any one time.
In single player, those two players can be switched around with two dolls that will act just like Link, and you can switch between Link and the two dolls. Whereas Four Swords Adventures had Link split up between different personalities, in Triforce Heroes, different players claim to be the hero of Hyrule.
There will also be a fashion element, where you can collect different outfits and items to pick up abilities, such as Zelda’s dress. Yes, after 25 years, you can dress Link as Zelda and it will be canon.
Nintendo also talked about the previously leaked Hyrule Warriors Legends. This 3DS version of the game is not a straight port, but is instead a reimagining of the Wii U version. Hyrule Warriors Legends will include all the DLC from the Wii U version, as well as additional characters/stages. You can learn more about Hyrule Warriors Legends here.
The Legend of Zelda Triforce Heroes will be released for 3DS on Fall 2015, while Hyrule Warriors Legends remains in development.