I just don't think it's feasible in the lifetime of anyone here.
Have a little think about the infrastructure required to support a pilotless aircraft at airports alone then have a think about the country you live in. Australia. A state government announces a long awaited rail line to Tulla airport, then tells you it will be ready in 10 years. Yep, 10 years to build a 20k piece of track. Mind you 10 years is nothing when you consider the airport has been there for 45 years or so before a rail link was announced. Badgerys Creek took 34 years to commence construction. It would be piss easy to pilotless an aircraft from the US to Australia, it's been done before but have another think about the infrastructure required and think about the incredibly average infrastructure that Australia is famous for, Australia 'the lucky country' not.