The only thing it would prevent is flying the aircraft INTO something or landing someplace other than the original destination. And even then, only if the pilot(s) are able to flip the switch. Since these (loosely identified as "human") terrorists are willing to destroy their own (useless) lives along with everyone else's, they can still destroy the aircraft with a bomb. This is the most costly, complicated and overly technological scheme I have ever heard of. It is a "committee-based" solution, and we know what most of those are like. :wackko: With so many possibilities for error and misuse I would never want to fly again. Not that I do it now, unless absolutely necessary, anyway.
I still say, it's just an early April Fool's joke, and not a funny one.