At its core, it is the same story as per usual. You play as the protagonist Link as he attempts to save the captured Princess Zelda. (Spoiler alert: he probably saves her). However, you also get to play as other fan-favorite characters from the universe. For instance, for the first time in the game series, players get to play as Hyrulean Captain Impa, Zelda's personal bodyguard and/or assistant. She is equipped with a huge sword that could manage powerful fighting combinations.
The other playable characters have not been announced yet.
Also, a new antagonist has been developed for Hyrule Warriors; a dark sorceress by the name of Cia. It's up to the player to defeat Cia and her army. Aside from that, some familiar enemies will also make an appearance.
As the press release states, "The game-play structure of most of the stages bears a close resemblance to the Dynasty Warrior games, so Hyrule Warriors is a game that can truly be enjoyed by fans of both The Legend of Zelda and the Dynasty Warrior series." It is difficult to tell if Hyrule Warriors will just be a clone of Dynasty Warriors or if it will show a close enough resemblance but can still be considered its own game.
In the end, Nintendo very rarely would mess up the Legend of Zelda series and the Dynasty Warrior series is known for its epic storyline. So, Hyrule Warriors promises to be a excellent representation of the series. More information will be provided at the next E3 Expo, as well as a playable demo if you attend the event.
Hyrule Warriors is set to be released in America for the Nintendo Wii U in 2014 at an undisclosed date, and in Japan in August 14.