I've been meaning to do a quadcopter design for some time, with some additional feature I don't think have been done before:
1) just use the main rotors for lift and maximum stability (on a very wide arm base), and use two additional propellers to push the copter forward. I'm guessing this would give it a much better stable video platform.
2) Fully autonomous, able to maintain a (rough) height of several meters above the ground, and away from side walls.
3) Have large foam floats on the base for possible water landings
The goal is to have it autonomously navigate a canyon (and film it). hence no GPS reception, little radio reception, and basically start it at the entrance to the canyon and have to come out the other end intact, without having to follow it on the ground (which is hard and maybe dangerous)
Dave.