I think the rub is that changing the wire is trivial - changing the things the wire connects is the tricky part....
So to keep or not keep a 3x75 ohm RCA connector really pales in comparison to the other concerns. I really like the concept of one wire to rule them all, so to speak. It would really start putting the hi-end interconnect folks on slippery ground too, which is where most of them belong IMO.
How many times have you noticed your hi-end ethernet cable brightening up and improving your ZIP files?
The protocol that gets pumped over that wire is the part that is going to take thought. If they're as far along as they say that should be ready for a 1.0 release I guess.