Google announced the release of the new Android 1.0 SDK.

Quotes:

Yes, that means we’re officially at 1.0. Of course the SDK won’t remain static—we’ll keep improving the tools by adding features and fixing bugs. But now developers can rely on the APIs in the SDK, and can update their applications to run on Android 1.0-compatible devices. The Android Market beta will also launch with the T-Mobile G1, providing developers an easy and open way to distribute their applications on that and later devices. I’ve already seen a lot of applications that have me stoked, and I can’t wait to see things really come together as developers cross that final mile to prepare their applications for Android 1.0.

http://android-developers.blogspot.com/2008/09/announcing-android-10-sdk-release-1.html