I think there are plenty of people out there, maybe not here on the SZ, but out in the mix who will be doing this within the next five years.
What am I smoking, you ask. All I will say is the name of the band is TOKEN!

I agree with Diki, that no one here has jumped up saying how they have to have all these features. Of course not, most of us are still musician- entertainers. Turn the paradigm inside out and this idea becomes a frightening possibility. Carry around a 52" monitor - not me, but have you seen some of the speaker setups these DJs have? You'd think they were playing Fenway Park or something.
Hey, us over-the-hillers are content to tweak our technology a little and buy a new keyboard every once in a while. But it won't be us who start this craze. I've got a few DJ friends who come close to this now. Add live playing and singing to the mix and it's a hit.
Yamaha was showcasing a double keyboard combo organ/arranger a couple years ago. I can't find anything about on the net right now, but it would our SZ answer to the C1 if we could get it made here. But now Roland is throwing this VIMA concept out there. The boards presently available are not viable for the commercial market, but if they wanted to they could put this into a 40 lb. package in no time.
I could be wrong, but technology is moving so fast, that I can forsee a 52" screen that weighs 4 lbs or less. Would you refuse to carry that? All this stuff is possible. Just because you don't like what you see and read doesn't mean it ain't gonna happen.