The add-on ands the following functionality to the Game Studio:
1. The ability to target and develop for the Zune HD media player.
2. The addition of new Touch APIs to the XNA Framework for use on the Zune HD.
3. The addition of new Accelerometer APIs to the XNA Framework for use on the Zune HD.
It also included documentation and examples integrated into Visual Studio Help that will show developers how to leverage the new APIs.
Unfortunately the software does not provide access to the 3D GPU on the ZuneHD, and also does not provide access to the internet. The lack of a distribution model for these applications unfortunately also make this a poor substitute for a real application development platform.