Developers finally got the green light to start working with all of what Android has to offer. Google today released the Software Developers Kit (SDK) for Android 2.1. The Google Nexus One, released Jan. 5, is currently the only Android device running Android 2.1.

According to the official Android Community blog, Android 2.1 “is a minor platform release deployable to Android-powered handsets starting in January 2010.” The release includes new API changes and bug fixes.

While the latest version of Android doesn’t offer any huge improvements over 2.0, which is now running on the Droid, it will enable developers to create animated wallpapers for the Nexus One, as well as other Android devices once they’ve been updated to 2.1

Google’s Nexus One has been the subject of considerable talk around the industry. The highly anticipated “Google phone” was launched prior to CES, with Google simultaneously launching its own online retail site to exclusively sell the phone.

Since then, a flurry of complaints about the phone’s 3G connectivity, as well as customer service, have surfaced on forums around the Web. Both Google and T-Mobile USA yesterday said that they were looking into the matter.