Google has released the final Android 3.0 Honeycomb SDK, complete with finalized APIs, on the eve of the first Honeycomb-based tablet being released. Developers now have the final set of tools to code for the Motorola XOOM and subsequent Android 3.0 slates, and the new API level is 11.
The Android 3.0 Honeycomb platform highlights are here, and there's a breakdown of differences between APIs here. There's also an update to SDK Tools (r10) and ADT Plugin for Eclipse (10.0.0), including such niceties as improved rendering of what the final on-screen app will look like.
Instructions for downloading the Android 3.0 SDK are here.