Copyright protection is a joke and the only way they can ever get it right is a private key encryption that has to be decoded with a public key on a licensing server, meaning inet required for DVD players. Funny that most of the new HD players do have a network port and even some modems....so who knows.
HD players are intended strictly for movies anyway, which will never be compressed down to 4/8GB when it's easier to make a bigger disc than to develop an algorithm. I don't think they even give a flip about the "backup/storage" uses of petty consumers. They just want you to have a reason to buy their HDTVs to go along with your new shiny violet-blue laser disc. No corporation in their right mind would ever consider it a valid method of backing up anyway. Tape/Disc libraries are a thing of teh past.
CD/DVD's in a protective cassette would be cool, sort of like a large floppy.
That came out 5 years ago. Maybe you've heard of DVD-RAM?
It crashed and burned, even with many million dollars of vendor support behind it.