The Legend of Zelda: Spirit Tracks was announced for as an official game on the 25th March, 2009 at the GDC by the Nintendo President, Satoru Iwata. Very little is currently known about the title; however, stick with us for all of the information you'll need!

The only information we do have is this small press release from the 25th March:

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.