To answer your last question first, no. There are other reasons why a lot of djs use/need a buffer of a table between them and the crowd. For me, it's having a table under which I store my cart and other stuff. Also, I need a place to keep my paperwork, keep prying hands away from stuff (you'd be surprised how many adults will just walk up and start messing with things). And it gives a way to create a focus, so for announcements, people know where to look when they hear the voice.
As for doing stuff like airwall brackets, I don't see that happening too frequently either (although it is a neat idea). The brackets I'm familiar with are $300 each, and I can't see the average dj, who bitches about the average price of everything (just go to prodj.com, djchat.com, or djgold.com and you'll see what I mean) to spend that kind of money. Even if they did, a lot of places don't give you the time to do stuff like that. I can't count the number of times I've had a 6 pm wedding and been told that there was another event ENDING at 4:30 or 5 PM in that room. So basically, I have to stage everything in the hall, and really hump once the room clears to move in and set up, then change into the tux and be ready.
So the short answer is yes, the technology is out there, but I doubt you'll ever see it implemented by the average dj due to cost, time, etc.