This is what Nintendo said, though: “The concept behind this Zelda game includes utilizing a steam locomotive to travel around the world, switching Phantom and Link to explore the dungeons, and solving puzzles using new items.”
So, all in all, the Spirit Tracks does sound a little like Phantom Hourglass: it features dungeon maps on the top screen of the DS, gameplay on the bottom screen, and some trains in between. There was also a trailer presented at GDC in which Link was presented as the engineer of a cannon train. Pretty cool, huh?
The Legend of Zelda: Spirit Tracks is scheduled to be released by the end of the year, exclusively on Nintendo DS.