We have already seen technology remove the radio operator, navigator and flight engineer. The co-pilot will be next to go and that is inevitable. Present Airbus aircraft aren't far off not actually requiring any manual input. It would only take the application of a small amount of already existing technology to make them fully automatic. Universal ADSB will soon be with us, starting the journey towards the elimination of human beings from the ATC loop. But hold on a minute! Strictly speaking ocean going cargo ships could have dispensed with human crews at least twenty years ago, they could proceed on a voyage automatically and only have a pilot aboard for docking manouvres. As far as I'm aware no ships have yet put to sea without human beings aboard. I wonder why?
The problem is that aircraft operate in a dynamic environment - or to put it in layman's terms the weather is changeable - so we still need a human being to supervise the proceedings. It will be a long time before the human Captain disappears, even if the skipper of a future 1500 passenger super A380 spends most of his time entertaining the first class passengers to dinner at his table, while his First Officer restlessly paces the silent bridge keeping a lookout for icebergs...