Impressive footage for sure !!!
But you will notice they are using a cleaver trick, they have something fixed in frame at all times, ie the birds head or wing, in my experience with playing about with cameras on the helicopter this distracts the human eye away from the pretty shoddy quality of the landscape, with out that in shot the whole thing becomes alot less impressive.
The problem with using things like birds or helicopters for a video platform at the tiny quick movements that make, of course with a helicopter you can create wonderful systems of servos and gyros to conteract that, but the ultimate platform has to be a large slow flying plane, they can take the weight and also offer a nice smooth ride for the camera.
And of course the main advantage of RC over a mother nature based platform is that it won't try and peck your eye out every time you give it a funny look
Cheers
Cris.