This whole thing has me really really pissed off. I really expected the govt would want to know what you are flying. So, they would know who to go after, if some RC pilot causes some damage.
Instead, they require a number they give you to be on every model you fly. How is that going to help? Unless you leave your model after you crash into something, and most RC pilots retrieve their crashed models to rebuild them.
All this does is allow the FAA people to come accuse those who do register, and since they don't have a list of what you are flying, they will accuse the nearest registered RC pilot.