To those that know of the TV Program "Top Gear" clarkson asked the very question to the audience as to who would get on a fully automated plane with no pilot on board - nobody would (this was during a discussion on fully automated cars).
I think the technical challenges could be overcome with the technology we already have - as Gengis points out communications redundency would be required but even without comms there could be a "safer" revert programmed. We have drones already in the military after all...
The bigger issue I think would be who would actually willingly get onto such an aircraft knowing that there is no pilot on board - it would take a complete re-education of the populous into placing our trust in such a aircraft as we like the console ourselves in the comfort that the guys up the front dont want to crash either (no matter how safer automation may be statistically).
Back to the original thread point - IIRC research was comissioned into introducing remote control/landing capabilities on airliners - not due to the Helios incident but after 9/11 to be able to take over control in Hi-jack situations. I am not sure if anything ever came of that but I recall reading somewhere they were exploring the possibilities.