Hello,
I don't think that GA will ever be banned either, nor do I believe that the FAA would ever come up with a scheme to make it cost prohibitive. There are too many forces in congress that would ensure our survival. When it comes right down to it, almost every pilot has some association with GA. GA is in fact the largest sector in aviation and employs more people, pays more taxes and fees and is also a business multiplier (just some buzzword there I thought I'd throw in).
TCAS in a 172? Well, looking at it from a business side it was the insurance companies that were the driving force in how the C-172SP was equipped. While TCAS might seem absurd to some it might be something that the insurance companies would demand in the future under the premise of safety. The real enemy of GA is not the FAA, but greedy insurance companies and ambulance chasing lawyers. Had it not been for the GARA (General Aviation Revitalization Act) the newest airplane we'd be flying would be 20 years old.
Just my .02 cents,
ex-Navy Rotorhead