I give it at least 100 years. There are many problems...
1. Judgement: No automated systems (even the best super computers) have the ability to respond to circumstances outside those which their designers anticipated. This is why the only automated ground vehicles operate in extremely controlled environments where there are going to zero outside factors (airport trains, mining trucks). This is the real kicker...it's not a question of applying current technology, this technology does not even exist yet. Sioux City type systems failures are very rare, but weather requires a lot of judgement on a daily basis.
2. Reliability: Current UAV systems have a non-combat loss rate of 1-2%. Airlines are more like 0.00001%. Any engineer can tell you that the first 95% is the easy part...after that it gets exponentially harder to ensure near-foolproof reliability. Airlines have that because the pilot can always hand-fly the airplane (and you have a spare pilot).
3. ATC: The entire ATC system would have to be converted to a system capable of managing and interacting with automated aircraft. In addition to technical and cost hurdles, the government red-tape will add at least 20-30 years to the whole process.
4. Security: An automated airliner would need a back-up ground-control link...if the bad guys jam it or hack it, all kinds of unpleasant things could happen (imagine 5,000 pre-launched cruise missiles awaiting targeting instructions
).
5. Cost: The cost and effort to develop and certify this sort of system would be comparable to the manhattan project...no single airline is going to be able to afford it, so who's going to pay? Managers would rather just spend $1 Billion on pilots this year than spend $10 Billion on a program that might save the company money in 30 years. I'm not sure the government would see a benefit either (spending billions to eliminate 80,000 pilot jobs???).
It is remotely possible that you would see single-pilot cargo airplanes in our working lifetime (at the end). If you go to work for FDX/UPS it is vaguely possible that your last few years as a captain might be lonely ones.
We can help delay the process by demanding contract language that the airline neither fund, encourage, or participate in R&D programs which would target pilot jobs. The managers will cheerfully agree because it's a long term issue and won't affect THEIR stock options in the next few years (after which they'll be long gone).