Forget the quadcopter, this looks way too cool!

[DrGeoff]

Japanese labs have developed a flying orb that looks really stable.

http://www.smh.com.au/technology/sci-tech/japanese-engineers-develop-flying-robotic-orb-20111027-1mkxi.html

[0xdeadbeef]

Looks like this essentially a vertically starting 3D-plane in an orb. Imagine an orb around this:
http://www.electrifly.com/parkflyers/gpma1135.html

The problem with this will be the battery time as when hovering, one (relatively) small propeller has to create all the lift. Also the torque has to be compensated via the control surfaces, so a part of the energy to create the lift is always lost to keep the device from spinning. Though the torque is smaller than that of a helicopter's rotor for sure.
Anyway, I would assume that the shown prototype will not be able to hover for more than a few minutes. A classical helicopter should be much more efficient when hovering.

Looks pretty stable though and of course it can really fly horizontally compared to a quadcopter.

[Achilles]

very cool!! Flying and moving around on the ground as a ball. Would be interesting about the Payload of such a thing and of course the stability in crosswinds.
Finally I can begin to build my Death-Star