In reply to andy:
Taking pictures: In a public place, take photos of who/what you like. You don't need "consent" from anybody to take photos, so not a problem. It's a camera - the rules don't change because it's on a drone.
The consent bit was more about if the people gave consent to the drone itself and not the filming.
However, there is still a potential problem with drones and invasion of privacy, etc. and I think it will be something that will need addressing at some point.
In the meantime, it would probably be a good idea for drone users to be sensible in how they're used and not use them in such places as built up areas and/or other places at busy times.
I should add, that I'm not anti-drone, as I see that they can produce stills and video from a totally different perspective and I'm considering buying one for that reason. For example, if someone was using one over 'insert beautiful place of your choice' at five in the morning, then it shouldn't be a problem. However, do it at noon on a busy Bank Holiday and it might be a different story...