The latest Avalon bits are now available (September CTP).  Tablet Avalon integration is included in the Avalon assemblies for all platforms and largely represents the APIs we will ship with.  There are only a few very minor tweaks we are making right now that will be in the next CTP.

To download, go to http://msdn.microsoft.com/windowsvista/getthebeta/default.aspx and click on the 'Download the WinFX Runtime Components – September CTP' link.

Enjoy!