The airline industry is consumer driven and will simply not take the gamble of introducing pilotless aircraft to the skies. The technology is already there- for instance the RAF operate pilotless drone aircraft already. However, like WWW says the infra structure which would be needed not to mention all the safety critical systems and the numbers of staff required would rule it out, in cost terms anyway- even if cargo aircraft were to be operated this way. One thing is to operate the odd pilotless aircraft from a remote site, but its quite another thing to operate day- in, day-out whole fleets of aircraft without pilots. Also any electronic device is liable to have its data corrupted by high energy cosmic rays- which there is no shielding for- so even if scientists invented true artificial intelligence it would be doubtful it could totally run an aircraft. There was a case a few years back of an automatic train somewhere near the Alps (I think?) that kept on going out of control. Teams of physicists and engineers were called in to sort the problem. Eventually they found that cosmic rays were actually changing binary digits within the train's computers.
I have a question for the rest though. Do you think avionics has reached its limit more-or-less? Where could the engineers go from here? Do you think it will ever get to the stage that a single button is pressed that will enable the aircraft to taxi, take-off cruise and land without the pilots intervention,- only during normal ops mind you??
It would been interesting to have asked the signalers, navigators and flight engineers back in the 50's and early 60's what they thought the future prospects of their job would encompass.