Twilight Princess' Agitha will be a playable character in Hyrule Warriors, as will a new character named Lana.
Update: Tecmo Koei released a large batch of screenshots today featuring Lana, Agitha, Midna, and even a few shots of Zant as an antagonist. Additionally, players can choose to dress Link and Zelda in their costumes from Twilight Princess.
Original story: The cast of playable characters in Hyrule Warriors, the Legend of Zelda spinoff in a Dynasty Warriors style, continues to grow with even more female characters. An issue of Famitsu revealed "princess of the insect kingdom" Agitha from Twilight Princess, as well as details on an entirely new character, Lana.
Lana is the White Witch of Hyrule Warriors and fights with a magical book. She can create walls to blow away enemies and shock enemies when the walls are destroyed. She is an original character created for the game. The antagonist of Hyrule Warriors is another witch named Cia, the Black Witch.
Agitha's only canon appearance in the Zelda series is in Twilight Princess where she tasks Link with bringing her golden bugs because she's a young, eccentric girl who loves bugs. In Hyrule Warriors she fights with her parasol and summons bugs to attack enemies.
Lana and Agitha join Link, Midna, Zelda, and Impa as playable characters. Tecmo Koei released a video yesterday of Impa's powerful long sword attacks. The Famitsu issue suggested Twilight Princess' Zant and the dragon Argorok will appear in Hyrule Warriors in some form.
Hyrule Warriors is very heavy on fighting, but players will be able to have some level of exploration beyond running forward and mowing down hordes of bokoblins. Link's hookshot will make a return for Hyrule Warriors, allowing players to reach previously inaccessible areas. And if that's enough, with certain strengthening items, players can bring down the moon from Majora's Mask on to enemies.
Legend of Zelda has many female characters who are never playable - due to the games being about Link's adventures - so it's nice to see the female-heavy cast of Hyrule Warriors.