We dealt with the same thing a couple years ago on Charter where I am, and most everyone does already have a box. But the state public access PR group threw a fit and forced Charter to keep on analog public access counterparts on the 90 tier, scuttling a much-needed channel shuffle and addition of a Spanish-language tier to our system (in a city with quite a large Hispanic population who can't be happy to only have Univision as their only Spanish choice). It took us three years to get even Telemundo and we don't have half the HD channels other Charter systems in Michigan and Connecticut get solely based on this. Two of the public access channels we get don't even work 90% of the time, one shows a still screen of their village hall all the time, and the last one is over-modulated to the point of constant buzzing and is unwatchable except on mute.
I would think though there is a declining amount of homes which utilize their cable-ready TV's to receive only what is passed through via analog cable. In a couple of years when all cable systems are digital-only, this won't be an issue at all.