Stuff is stored in bytes. It's all computerised.
So the optimisation lies in the transfer of these bytes, from one place to the next. Regardless of what quality is being used (DVD or HD, or even just VHS). Transport can always be optimised.
The most optimal is transfer over the internet -- no need for trucks with physical media on them, or anything like that.
All the technology is already here. It's just that the movie industry execs fear mass piracy so don't want to create an easy system.
In the states (and soon here hopefully), Apple and others are already doing this. You can get a little box under your TV that connects to the internet and lets you rent films. It takes about 30secs for it to load enough to start watching, varying with your internet connection.