[rabbitc]

its more logical to just rent or buy HD

I agree - what I'm questioning is why it has to be an optical disc. I think optical media's days are numbered (and I'm not alone in that thinking)

Optical media served it's purpose at a time when solid state technology couldn't offer the capacities and the advantages of non-volatile power-off states.

But all that has changed now. In fact, if it hadn't been for DVD and CD before it, it's unlikely that Blu-ray would have ever caught on in the first place.

Even Sony doesn't believe in it's own formula - it has a full line of HD camcorders shipping with solid state storage. Why? Quite simple: reliability, durability and life.