Google has released the Final SDK for Honeycomb, so that developers can get cracking with tablets apps. In a post on Android Dev Blog Google said:
We are pleased to announce that the full SDK for Android 3.0 is now available to developers. The APIs are final, and you can now develop apps targeting this new platform and publish them to Android Market. The new API level is 11.
Along with the SDK, Google has also released updates to SDK Tools (r10) and ADT Plugin for Eclipse (10.0.0).
More on SDK here.