In The Legend of Zelda: Spirit Tracks, there is more to Zelda than meets the eye. No, she doesn't transform into a car.
This new Legend of Zelda: Spirit Tracks trailer shows us that Zelda will co-star right alongside Link for presumably the entire game, partially taking on a companion role similar to that of Navi. However, Zelda will also have the power to do much more than fly around your head and yell "Hey!" In Spirit Tracks, Zelda can possess enemies to help Link get through certain parts of the game's dungeons.
In the trailer, Zelda gets zapped by an enemy's powerful magic, turning her into a sort of spirit. Part of Link's goal in Spirit Tracks is likely to change Zelda back to normal, though Zelda's form does allow her the power of possession. This power could be limited to only the phantom knights shown in the trailer, but it would be very cool if she could inhabit other forms as well.
It's nice to see that Spirit Tracks will be more than Phantom Hourglass with a Choo Choo Train. When Zelda is in the body of a phantom knight, she is able to block streams of fire so Link can pass by, and can carry Link across dangerous areas. New items are also shown off in the trailer, including the whip (that looks like a snake) which gives Link the ability to swing across chasms, whip enemies, and pull switches, and a brand new item that fires off a whirlwind.
I always look forward to the creativity that comes from every high profile Nintendo title. Fanboy or not, I even enjoyed Super Mario Sunshine. This holiday season will only see the release of two: The Legend of Zelda: Spirit Tracks and New Super Mario Bros. Wii, but they are both looking great. Now, if I can just finish Phantom Hourglass before Spirit Tracks' December 7 release date.