Air will be fine, as 99.9999% of these won’t be operated anywhere that could be remotely construed as a manned aircraft flight path.
Chaos on the ground will be from ignorant arguments over whether it need be registered, and how that registration requirement will be grossly abused (ex.: you record police violating a law, and they slam you with a $250,000 fine for using an unregistered drone for the recording).
It’s guaranteed that if you irritate your neighbors by the way you use your drone, they’ll go after you and use the registration issue. That’s how this regulation will be enforced, and, most likely, strongly enforced.