actually they do support it to some little degree, search on it there is a lot of work with it... but the moral of the story is it sucks.
http://www.xboxmediaplayer.de/cgi-bin/foru...t=ST;f=4;t=527;Supported input media formats and devices:
- Read files directly from a CD, VCD or DVD media in the Xbox's DVD-ROM drive**
(Support CD/DVD formats: ISO 9660 - Mode1/2/XA, UDF 1.02 and XDVDFS/CDX)
(DVD-ROM playback is on-the-fly only** (no option yet to auto-cache to HDD first)
- Play files directly from Xbox built-in hard drive (copy first from DVD** or network)****
- Xbox Memory Cards (note that only FAT-X formated memory cards is supported)****
- Stream media files from a computer over a local network via XNS*, XBMSP or SMB,
(including all NAS, Network Attached Storage devices that support SAMBA/SMB).
- XBMC XBMSP-client code updated to support "Auto-Discovery of XBMSP servers"
- Stream supported media files from the internet (if stream format is supported too)*
- iTunes Music Shares via DAAP (network stream from Apple iTunes on Mac or PC)*****
- USB Mass Storage Devices (USB-HDD's/memory) with FAT-X filesystem** = Experimental, unfinished, unstable, buggy and/or limited