The Air Force is supposed to be establishing a separate AFSC, like you said, to operate UAVs. Operators will no longer go to Pilot Training. They'll go through UAV training. Still, there are rated guys going to fly them. My guess is rated guys will always have the option to go fly UAVs although the main force of guys will be from the new track of homegrown UAV operators.
As far as the future of UAVs, in my opinion, it will include everything other than cargo and possibly tankers getting switched to UAVs. The air to air role could be switched over tomorrow and would improve our capability and costs extraordinarily. Of course the Air Force is run by fighter pilots and they want to fly that F22 and F35 (that we just had to have) so they may be the last to switch over simply due to politics even though they should be the first.
The future will also likely bring more mid air collisions since UAV operators have absolutely no time or concern for the people actually flying in the air. They have typically one sensor, padlocked on a target, and do not scan for air traffic around them. They don't talk on radios in many instances so manned aircraft can't deconflict, they're being mass produced and growing every day, and are often flown by the lowest common denominator who is unable to spell UAV. It's only a matter of time before these skymines start making headlines.