Right now, it is only possible to get HD-sound without downsampling with TotalMediaTheatre using analog outputs.
Unfortunately there are only four discs available which really have a 24/96 soundtrack, yet. All the other discs using LPCM, DD TrueHD or DTSHD MA only have 24/48 or even only 16/48 like a normal DVD.
More about it here:
http://www.avsforum.com/avs-vb/showthread.php?t=760714
Watching the Chris Botti disc on my HTPC, TMT, Reclock and my soundcard's driver display 24/96 @ 13500kbps.
The problem is not about the players but about the movies which neither have 96kHz nor 192kHz soundtracks...
Regards,
nosurrender