Well, at one time you DID have to have a license to operate a remote controlled aircraft, from the FCC. I go back far enough that when I started flying R/C sailplanes in 1975, I applied for a non-voice license from the FCC to operate my radio. Cost 25 bucks for five years, if I remember correctly. When the CB radio fad hit, I got a voice license also, same price. I think I have both of them still around here somewhere. After a year or two of trying to deal with the crush of CB radio applications, they did away with both. This put TV and radio stations up in arms, but that's another story.
The hobby shop sells very small quad copters, about the diameter of a baseball, and they go for about 30 bucks, might even be cheaper now. Somehow a line has to be determines what size/power/range dictates what gets registered. That will be interesting to see.
I'm in favor of licensing any commercial user such as photographers, real estate firms, anyone that uses these as some sort of tool, which I am all in favor of also. Sport flyers of certain size/range/power output would fall under that also. They are the real problem in my concern. The big fine mentioned in the link is the first I've heard of, but should set the precedent and bench mark. We are talking the possibility of people getting killed, and potential for large property damage and loss if a serious mid-air occurs.
Time will tell,
Dan McEntee