unmanned is the operative word. Unmanned flight operations are not even new anymore, at least in the military. There will no doubt be bigger and bigger unmanned a/c, especially in the military role but as soon as you start on about 'pilotless' aircraft and passengers you will see a totally different response.
As far as I am aware the only 'driverless' vehicle you will see anywhere will be a train, and then only on short uncomplicated routes such as the Docklands Light Railway or the little shuttles that move you from terminal to terminal at airports.
People, it would seem, only trust automation for one dimensional travel. We haven't even started on two dimensional and alreacy we have journalists claiming we are as good as redundant when it comes to three dimensional transport.
There will probably come a time when there will be pilotless aircraft that will take pax but dount count on it for at least 5 generations if not more. Never say never!