Registration is going to do absolutely nothing other than be a cost and inconvenience for safe and law abiding drone users. Anyone that wants to use a drone to do harm or fly in a restricted airspace is going to build their own and ignore the registration requirement.
Before anyone jumps to, "we need to restrict the sale of drone parts!", it's not gonna work. The parts are cheap and readily available. All you need to build one are some electric motors, a battery, an RC transmitter & receiver, and a flight control board, oh, and some open source software. Keep in mind, the pioneers of hobby drones used the remote control from your kid's Nintendo Wii connected with a simple off the shelf board for their flight control boards!
The only thing excessive and pointless regulation is going to do at this point is prevent the advancement of drone technology for beneficial and commercial uses.