While the Nexus S isn't available quite yet, that didn't stop some enterprising hackers from fashioning a re-work of the ho-hum boring original Nexus live wallpaper into the beauty you see above. It's easy to install (yes, you have to be rooted), but it does overwrite the original -- so back that up if you want to keep it.
We've got it working here on the Evo 4G and the Droid Incredible, but didn't have much luck on the Droid X. Your mileage may vary. Check it out, and get the download and full instructions in the Droid Incredible forums. [Android Central Forums]