2 hour movies on Bluray are taking up ~22GB with MPEG2 encoding, the same as DVD. So maybe 40 minutes of 1080p24 video on a dual layer DVD. Not sure what you would want encoded, but 1080i60 and 720p60 are also in the same ballpark.

Moot point, really. Copy protection and studio paranoia are the reasons this doesn't already exist. Toshiba will have an uphill battle bringing that to the USA. At least in usable form. If all the transmissions are copy protected, it won't have anything to copy.