The xbox 360 will play high def HDDVD movies if you buy an external HDDVD drive (now an obsolete format though) and can also play high def video files stored on its hard drive, network or from xbox live. Your Panasonic upscales which means it takes a standard definition source and interpolates it upto a higher resolution. This can be quite effective on some sources. However a high definition tv does exactly the same thing when it gets a SD source. Generally as long as the dvd recorder is connected via a digital signal (hdmi or dvi) is all thats important to get the best picture and the resolution setting won't make much difference. If you have a cheap high definition tv with poor upscaling then its likely the Panasonic dvd recorder will do a better job than the tv. The Panasonic upscaling won't be as good as some Toshiba XDE upscaling dvd players or standalone HDDVD players they do a much better job of it but its quite respectable upscaling on the Panasonic.