So far, what we've gotten on the DS is either of these three:

1) High-quality visuals (far better than the N64)
2) Ports with average visuals (only slightly better than N64 at best)
3) 2D games that aren't worth a second look at to judge visuals (with a few exceptions)

With Mario Kart and Metroid Prime: Hunters, it looks like we're getting option #1. That's always a good thing. I'm very happy to see such games in developement. Now, we need the third parties to do the same. Pretty soon we'll have games on the DS that are worth the time to look at just to see the visual quality. NFSU2 seems to be one of the first few games that will accomplish this. We have so far only scratched the surface of the DS' graphical capabilities. I, for one, am quite excited. :D