Spurious RF might not "take down airplanes," but it is not hard to imagine it having an effect on various aircraft systems. For instance, aircraft SATCOM uses 16XX MHz for uplink. I could imagine a poorly designed/tested/repaired 800-band cell phone outputting a second harmonic, which could interfere with this communication. It might not cause the plane to crash, but it could increase pilot workload or prevent important communication with the ground. This is a bit of a contrived example (since SATCOM would not typically be used during takeoff or landing), but still there is no way for flight crews OR passengers to know for sure if their equipment is compatible with each other. We can be even less sure about UNintentional radiators...especially cheap gadgets with switching power. Takeoff and landing are the most dangerous phases of flight - I think a bit of regulation is warranted in this case, especially since the inconvenience is so small. (disclaimer: not an RF engineer, so maybe I just don't understand the issue fully)

Personally, I'm glad they used the radeon 9200 chip. It makes the mini more attractive to me as a linux box because the 9200 is the best chip available right now with opensource 3D drivers. Remember, NVidia's and ATI's binary drivers don't work on the PPC architecture.