Let's talk about art styles.

Toon Link was really good in Wind Waker, I liked him a lot and still do. But, there's two reasons I don't want to see him again: First off, he looks awful on the DS, an absolute monstrosity; Second, he's a very unique design, unlike anything else in the series, so he fits much better as a one-off thing, something I like to see once but not much more: He's worn out his welcome at this point.

Twilight Princess Link was amazing. He is definitely the future I'd like to see in the series.

1-0 for Wii Zelda.

Next, let's talk about overall gameplay, the dungeons in particular.

Spirit Tracks' dungeons look just as simple and uninteresting as they did in Phantom Hourglass. Simple puzzles galore and very simple palette-swaps up the arse. Seriously, we're BEYOND simple palette swaps and the same music all the way: There was no excuse for Phantom Hourglass and there certainly isn't for this game.

We have no idea how Wii Zelda will play, maybe somewhat like Twilight Princess? With slightly better level designs and higher difficulty that's already way, way, way better than Spirit Tracks.

2-0 for Wii Zelda.

Now let's talk aboot dem gimmicks!

Spirit Tracks has a train.
Now, I'm not complaining about the technology, but it looks like it'll have the exact same "plot course and slog forward at minimum speed in an almost entirely feature-less overworld" as Phantom Hourglass did with the steamboat.
The dark nut better be utilised really ****ing well.

Wii Zelda has...that other character, maybe we can control it in special ways with the Wii Motion+?

3-0 for Wii Zelda.

Graphics: They're both 3-d, but one is on the DS and the other for Wii. If Spirit Tracks was in 2-d I would maybe consider it for a single moment, or even if it tried for one moment to look any better than Zelda 1 and Adventure of Link, but so far the Wii Zelda already looks way better.

4-0 for Wii Zelda.

It's pretty one-sided so far, yeah.