UAV's also have weight issues. The shadow, the one mentioned in the article, doesn't have any kind of radar, heck it doesn't even have brakes. This is due to the very reliable but fairly weak engine it uses. It's internal computer basically only handles the inertial nav system, the communications, and maintains straight and level flight. The ground control station makes all the actual decisions. If the AV loses contact with the GCS, it's preprogrammed either to return to a predesignated coordinate and fly a loiter pattern (hopefully getting signal back again on the way), or to deploy it's parachute.
In other words, nevermind avoiding another aircraft, this thing will fly into a mountain if allowed to fly itself. I believe that the reason that this aircraft is the one being selected for FAA approval is because of it's reliability at doing it's job even with it's limitations, not because of it's feature set. My unit, and many others, have never crashed one of these UAV's. Other UAV's, even more sophisticated ones, fall out of the sky all the time. While the shadow is not perfect, it is definately going to be the benchmark in the future for how rugged and simple versus how feature rich a UAV needs to be.
All seems condemned in the long run to approximate a state akin to Gaussian noise. -- James Martin