The guys at LegitReviews have come up with a way to use the HD-DVD player from an XBOX 360 with their HTPC. HD video for less than $200 sounds pretty damn good to me....

"The Xbox 360 HD DVD player was connected to the HTPC via the supplied USB cable and plugged into a power source. After connecting the HD DVD player to the computer with nothing more than the USB cable we can now worry about getting the HD content from the computer to the television with the HDMI cable."