A new CVS compile (by T3CH) of XboxMediaCenter has been released.
This T3CH-compile is a BAREBONE package (with just a few thirdparty scripts and with just the default skin) compiled with XDK v5849.

Here's the full changelog since the 2005-09-12 CVS release:
* added: wrapper class for dll's (See DynamicDll.h for more info)
* added: Milk drop now supports stereo 3d mode.
* added: AC3-wav, AC3-cdda, DTS-wav and DTS-cdda playback to paplayer. NOTE: DTS-wav and DTS-cdda will always output as AC3.
* added: MasterPassword: Audio & Video & Picture -> Context menu - Settings will now also check for MasterPassword if Lock Settings is enabled! [GeminiServer]
* added: logpath for xbmc.log file! Set the path where the log file should be created. [GeminiServer] If no path is set the Default Q: path will be used. Example: E:TDATAface008
* added: New builtin command: XBMC.Notification(,). Will show a KAI toast dialog with the specified header and message.
* added: Display of type of audiostream (Commentary, For Hearing impaired on those dvd's that support it)
* added: Alternative ascii-gfx Filezilla (FTP) Welcome MSG. Disabled by default, to enable, first disable (comment) org. MSG, then uncomment new MSG. Use an ASCII capable font for display in ftpCLIENT. Thx to h8!
* changed: reversed and fixed double xboxmediacenter.xml settings issue if home path was set [GeminiServer]
* changed: reorganized the Homedir log structure! [GeminiServer]
* changed: disabled software upsampling for multichannel audio (>2). (MPlayer, DVDPlayer)
* changed: disabled software upsampling for multichannel audio (>2). (PAPlayer)
* changed: disabled crossfading for cdda.
* changed: context menu Audio & Video & Picture -> to avoid large context menu, grayed out context menu items are now removed! They will displayed if required!
* changed: minor improvement for vertical chroma alignment in PixelShader Renderers. it was off by half a pixel.
* changed: XBMC.AlarmClock() can now execute any builtin. NEW SYNTAX! XBMC.AlarmClock(,).
* changed: Playlists skip to next song when it an unplayable item is encountered
* changed: dvdplayer now select and show audio and subtitle streams, soly based on what's specifed in ifo files. mapping of this to the mpeg streams should now be correct too
* fixed: reading settings from xboxmediacenter.xml was broken! This should solve other issues! [GeminiServer]
* fixed: manual authentiction for smb wasn't working
* fixed: when set to dhcp, samba wouldn't be set to use the correct interface.
* fixed: with crossfading enabled a new track with a different amount of channels as the currently playing file could not be started.
* fixed: Audio Context menu - Rip CD Audio: AudioCD Detection was brocken/wrong. Also add. CDExtra and MixedMode detection to enable Rip CD Audio! [GeminiServer]
* fixed: dvdmenu jumps when selection is changed
* fixed: z: is now mapped to the correct drive.
* fixed: DVDPlayer was unable to play .ac3 files
* fixed: DVDPlayer wouldn't display subtitles unless the subtitles visible option was toggled of and on in osd
* fixed: DVDPlayer didn't display anything when in the background
* fixed: DVDPlayer would play horribly choppy when there was no audio stream present

The T3CH nfo also informs there's a new, easier way to install XBMC as your dashboard:
[QUOTE]
Thanks to a new app called 'Team UIX's Xbe Shortcut Maker v1.0' by JbOnE, it's now extremely easy:
Edit XBMCxboxmediacenter.xml to your liking & transfer contents of XBMC folder TO (this is VERY important) "E:APPSXBMC". Rename <> to something your bios can boot (see here or read your BIOS README) and transfer to your C partition. No need to fiddle with HOME tag anymore, and future upgrades you won't need to worry about this file on C.
[/QUOTE]

You can add more scripts and skins yourself if desired. You can download them from allxboxskins.com, xbox-skins.net and xbmcscripts.com.
Keep in mind this is a CVS snapshot of the current development tree. It's not a official (stable) point release. Use only if you know what you are doing.