Isn't this lack of definition the issue? If I understand the answers correctly it seems to be a general view that technically one can do much more than the world is ready for, or certainly more than the world is ready to sign off as being perfectly acceptable to have around interacting with other air traffic and the general public.
So if we are saying we can test airframes, systems and they can't be broken, where are the challenges to getting UAV's signed off?
As has been said there are vastly more civil uses for UAV's than in the military but currently even our military ones can't be flown around the UK so what chance any civilian ones being used?
One could easily see a role for UAV's in place of, say, Police Helicopters but surely the role of getting them accepted is a role for testing organisations to agree how to sign these things off and convince those that need it that these are safe - or can be made safe?