The HD WMV DVD will not play back on set top DVD or Bluray players. A HD-DVD or AVCHD Bluray burnt to standard DVD will play back on HD or Bluray players.
The HD WMV DVD will play in Windows Media Player or Media Center on a computer connected to a high definition monitor or HDTV. They will play with menu for navigation.
The resolution that the HD WMV DVD will play at on a computer and monitor will depend on the monitor resolution. For example I have a 22" widescreen monitor with a resolution of 1680x1050... therefore a 1280x720 HD WMV DVD would play at the full 1280x720 resolution and can be scaled it to fit the screen. A 1920x1080 HD WMV DVD would be scaled down to fit the screen.
The HD WMV DVD would play in your Media Center PC and if connected to your HDTV it would play back at the high definition resolution of the HD WMV and be scaled to fit the screen. So I play them on my home theater PC connected to my HDTV via HDMI connection.