For ATC to take over the helm of a plane in trouble implies that there is no-one on board the aircraft capable of piloting the aeroplane, otherwise someone would.That only leaves a few possibilities.
The first is that the pilots are all dead or incapacitated and the hijackers cannot fly the aircraft - pretty dumb move on their part! Otherwise any pilot trained terrorists would disconnect the remote flight system and do what they wanted with the aeroplane. At least, the terrorists would simply find some way to crash the aeroplane, such as shutting down the engines, rather than be flown quietly to jail.
The second possibility is that the FAA is thinking in terms of gassing everyone on the aeroplane to secure it. Then the plane would have to be landed from outside.
The third possibility is that the Feds are thinking of installing some sort of automatic system which is totally separate from the normal aircraft control system and which can be used to over-ride them. Next time ATC says "hold 210 till the marker" they can just fly the aircraft for you!
Where is Boy George getting his ideas from? No wonder security is a mess if the same people are advising him who bought up this idea. The FAA cannot even keep their present radars working. Any high tech. system they have tried to install has been a disaster with massive delays and cost overruns. How would controllers be trained and kept current? What technology would be needed? The aircraft installation alone would be enormously complex and expensive.
Sounds like a turf grab by the FAA to me.
How many sky marshals could you buy for the R&D costs of this project? To be more accurate, it would probably be cheaper and quicker to buy a few of the more troublesome countries than finance this idea.
I sure hope it works better than the missile defence system!