If the FAA think this will stop someone from using a "drone" in a manner that could cause potential harm to an airliner, well, they are fools. Look how well the anti gun law in Chicago worked. The law simply states, it is illegal to be in possession of a firearm. Yet, how many shootings have there been when this law was in effect.
I for one am not going to register
I for one will continue to fly under the AMA Guidlelines, and until such time that you have to present to go to a Fly in, I will go to Fly ins.
Registering will not make me a safer flyer, I already am one, all it does is puts me on a fly list. Great, another hackable list that will have my information on. No Thanks!
Good luck enforcing this, no LEO will waste his time checking if a RC plane flying at a club field has a registration number.
BTW, when the next AMA ballots come out, vote out whoever is currently there.