The TV channels cost massive amounts to the cable company, too, though. Internet prices wouldn't have to change much. Comcast is a particularly special case because they own a bunch of channels (NBC Universal), though - others have much smaller footprints.

But agreed that the realistic threat isn't Netflix or Youtube or Sling or Hulu, it's wireless broadband. I'm not as optimistic as you, though, based on my experience with cell phone service in my apartments. :|