A new version, based on the cupcake branch, is now available on Android Open Source Project. The main improvements include soft keyboard support, home screen widgets, live folders and speech recognition.

The new SDK is backwards compatible with 1.0 and 1.1. That is, you can run old code on the new version of the OS. As with all OS platforms, there have been minor changes and fixes to functionality that mean that there will only be some minor side effects running old code on the newer OS.

It’s good to hear Dianne Hackborn, Android Framework Engineer say…
“A major goal for releases since 1.0 is to not break existing applications that are using the official SDK.  Some times there will be things that break, unintentionally, so you will want to test against current builds, but that should very much be the minority.”