"[W]e are pleased to announce the immediate availability of XNA Game Studio 3.1 Zune Extensions to support Zune HD. This add-on for XNA Game Studio 3.1 adds the following functionality to the product:  The ability to target and develop for the Zune HD media player.  The addition of new Touch APIs to the XNA Framework for use on the Zune HD.  The addition of new Accelerometer APIs to the XNA Framework for use on the Zune HD."
Even though there's still no word on an official apps distribution platform for Zune HD, intrepid developers can still make use of some of the device's cooler features using the same XNA framework that worked on the older Zunes. Even just a few days in, developers are already starting to try out the multi-touch and accelerometer APIs like in this etch-a-sketch program (video below). Sure, it'd be nice to see some real apps available for purchase through the Marketplace, but for now I'm just happy the device is still somewhat open. Other downsides include the lack of HD-specific graphics libraries (everything's still 2D SpriteBatch-based, so no epic FPS's yet) or internet-aware niceneties.