The only way its going to keep going up is if the cable TV providers are content with a shrinking market. If the average cable TV bill hits breaks the 200/month mark, the majority of people will eliminate TV from their wants and needs and will settle for internet only. Many will opt for a smart phone and tablet computer only and get their internet solely from free wifi and cell phone providers.
I know I already eliminated TV and land line phone service from my home years ago. I am down to a flip phone and a cable modem. at some point in the future, I may ditch the cable modem and upgrade to a smart phone with premium data plan and a cellular modem.
You can’t really go to the cellular network for broadband. They are having issues keeping up with demand. ATT recently jacked up their data plan from 25 for 2gigs to 30 for 3gigs. You go over that, you spend another 30 bucks. Streaming videos to watch instead of cable will not be practical like that. Every carrier except Tmobile that I am aware of, have got rid of their unlimited data plans.
Cell phone companies on the whole are experiencing rapid growth in data usage due to the smart phones. They will rapidly hit the wall where there is no more spectrum to buy.