It might not be comcast that dies, but rather a couple of the cell phone vendors. Those are the businesses that are making bank on what is basically low bandwidth wide area coverage. Given the transmission path is going to be going up, it seems that a lot of the existing problems with topology and buildings getting it the way will be reduced.

Anyway, I'm in a town with google fiber, but can't get more than a 30Mbit uplink on spectrum (which is actually faster than AT&T) because the only places in town with competition are the areas already served by google fiber.

It won't take much to kill these lumbering giants that refuse to invest in their infrastructure. Particularly given the ill will most people feel towards them.