Google’s Android mobile operating system just released a long awaited upgrade to its software development kit (SDK). The 0.9 beta is now available via the Android Development center.

According to the Android developers blog, there are a slew of new features and bug fixes, most notably:

• First and most obviously, the new Home screen is included, along with a ton of UI changes for 1.0.
• Some new applications are included: an Alarm Clock, Calculator, Camera, Music player, Picture viewer, and Messaging (for SMS/MMS conversations.)
• Several new development tools were added, such as a graphical preview for XML layouts for users of Eclipse, and a tool for constructing 9-patch images.
• Since we’ve got a new Home screen application now, we thought the now-obsolete version from the M5 early-look SDK might be helpful to developers, so its source is included as a sample.
• A number of new APIs are fleshed out and improved, and others are now close to their final forms for 1.0.
• Tons of bugs were fixed, of course. (If you had problems with the MediaPlayer, try it now!).

The SDK provides the much needed tools and code needed for third-party developers to write applications for the system. In fact, Android developers have metaphorically grabbed their pitch forks and torches over the delays in delivery. Even a petition for an update has made the rounds. For potential Android developers, hungry for an open mobile platform to build upon, this update is a very welcome and will be closely scrutinized.

The SDK comes the same day the HTC Dream was announced as the first mobile handset to carry Google’s mobile operating system. If the timing is any indication, this SDK should be much stabler than the previous version — a version developers were cautious to develop for due to lots of questionable hardware integration issues and bugs.

Packaged with the SDK is an emulator, which allows us a chance to take a peak at what the new Operating System looks like. Screenshots after the break.

The Android home screen

The application menu

The dialing application

Android’s Browser

Google Maps in Streetview, a feature not available in other mobile versions.

The Android music player