No firsthand experience in commercial aviation but somewhat involved in contemporary safety research, and therefore I definitely side with the skeptics concerning total automation. All talk about "80 (or whatever)% of accidents caused by human error" nonwithstanding, there is now wide and increasing agreement that frontline staff "create safety through their practice of reconciling multiple goals in complex, dynamic settings"*). I dare posit that a system as large and tightly coupled, exposed to a quickly changing environment (e.g., weather, congestion and delays etc.) can never be successfully preprogrammed and operated from the back office.
*) S. Dekker, The field guide to understanding human error, Farnham: Asghate, 2006, p. xii