At the Game Developers Conference Iwata has announced that a new Zelda game will be released for Nintendo DS later in the year. In the game Link has the ability to control/create enemies and make them fight other enemies.

The game will feature a railroad mechanic that looks to be an extension of the boat system in Phantom Hourglass, you can ride on a rail and shoot cannons.

Much like Phantom Hourglass, this game will feature the cel-shaded 'toon' style pioneered by Wind Waker.

Official Press statement:

The new The Legend of Zelda™: Spirit Tracks game that Iwata announced will utilise the intuitive touch control of Phantom Hourglass in an all new adventure that will please longtime Zelda™ fans while keeping the game accessible to all DS owners. The concept behind this Zelda game includes utilising a steam locomotive to travel around the world, switching Phantom and Link to explore the dungeons, and solving puzzles using new items.

Trailer:

Screens:
(via Joystick.com)

We'll post more info when available.