I work for a company that lives uav's and works very closely with Congress, the FAA, and other federal agencies. Anticipate limitations and active restriction of r/c modeling in the not very distant future. That association of involvement is precisely why some (including myself) have mentioned that we need to scale back some of what we have been doing. The ultra large models will require operator certification from a federal agency to operate, and weight limitations will also be imposed. Look to regulations about to go into place in Europe and Australia as reasonable guidelines. Ours will be similar. If it's over about 25 kilos it will be an issue. It could end up less than that since so many highly successful uav's are well under that amount. If you're flying something ultra large now enjoy it while you can, because it's not going to last.

The governing body for U.S. airspace use is still the FAA in conjunction with the NTSB. They merely tolerate other agencies of any type with the exception of the military. Everyone else has no real authority.