Western Digital just released a MAJOR (beta) firmware update to the "Live" series of WDTV HD media players.
http://www.wdc.com/wdtvlive_prerelease/
Be warned that various WDTV forums indicate this FW is still quite buggy but it IS a Beta...
The good news (for me at least) is this new FW introduces DVD navigation and menu support!!!
Cheers,
BR