Users of XBMCbuntu have not gotten to enjoy the recent labors of the XBMC team, as all major alpha releases have been exclusively built for OSX and Windows. While no official alpha releases are available from the Team, sraue and XBMC Freak are currently offering up an extremely alpha release, if you are comfortable dealing with some almost guaranteed bugs. This release includes the already discussed AudioEngine goodies, XvBA for AMD Radeon users, and more.

You can download it from XBMC Freak.