A fashionable bike helmet isn't really "saving the world" by any stretch of the imagination, but it's a nice video.
Anyway, airbag vests already exist for motorcycles... There are various designs, protecting the body and the neck. I've never owned one, but it looks like they typically operate using a cable which is attached to the motorcycle and a CO2 cartridge. Cost is similar, maybe $500, and they are usually reusable assuming they aren't actually tweaked in the crash.