As far as I know, the HD-DVD folks closed that format down years ago. I was at CES the year that Toshiba admitted HD-DVD had lost to Blu-Ray. A tough moment for them.
Yeah. They really got railroaded.
Anyone who still has the equipment can compare the HD-DVD of the Eagles Farewell Tour Vol 1 to the BluRay of the same concert and see how far advanced HD-DVD was with regard to menus and usability. But first you have to find that someone.
It was a good move in the long run, however, to solidify on one format, but I digress. The chances of having any new HD-DVD disc released are even lower than seeing a new release CD-4 Quadradisc in a local retailer!
Sadly, the whole disc based "battle" was really for the short haul, as sales of these things are going in the tank thanks to streaming, Netfix, Hulu, Amazon, DirecTV, cable, etc etc. Having a library of music or movies will be a nostalgia thing in 15-20 years.
Walk into a Costco, Sams, etc, these days and look for the movies. It's a shadow of what those sections once were, and try and find a CD in those stores these days.