Ulead software now supports
HD-DVD disc creation, suggest you check it out.
Ulead VideoStudio 10-plus will convert to HD then author a disc. Do you have some of these discs lying around to burn, and a HD-DVD burner?
If your player supports playback of MPEG-2 or MPEG-4 files from DVD that are in high-res formats, that might be another way to go.