It is interesting to note that the new rules register the owner, not the aircraft. You can have a bunch of drones, but only you are registered, sort of like a pilot's licence.
Aviation authorities in other countries will be watching this, and you can expect similar laws to be enacted in other countries.
I think the intent here is quite simple and legitimate, they want to be able to identify any drone that causes problems. If you register early, it costs you nothing, and if you fly safely, then it has no bearing on you.
The libertarians on the drone forums are totally up in arms over this, but mostly these are the people who rail against any authority.