Love the smooth zooming. That's always bugged me with online maps. And it zooms so quickly, even when encountering new info on a relatively slow connection.

Color me very impressed. Though I am with devonrt on this: other projections?

Looks kind of neat, but I always thought it was a shame that spherical mercator has become the standard projection for web maps; it's kind of ugly.

http://mapbox.com/ has some simular maps

Doesn't work in Firefox 3.0.x