If I can tag on to Scott's reply...
I've seen lots of ideas on computer management of traffic for decades now. The general concept may work in an enroute environment where the vast majority of traffic is IFR with known, defined flight paths.
In the terminal environments where I've spent my career, I just see no way for a computer to anticipate all the user's needs. I want to see a computer than can anticipate where a pipeline patrol, police copter, medivac copter, sightseeing or VFR training flight will go next. How would a computer figure the trajectory of a T-38 that wants multiple approaches followed by a couple overhead patterns? How would a computer sequence an FMS equipped Boeing with a VHF nav/com only Cherokee or Cessna?
I guess the point being that even if a computer can separate and sequence to a point 30 miles from the airport, it doesn't solve the problem of getting the aircraft on and off a crowded runway, over a blocked taxiway, to an already occupied gate....
