I think this is what GloryStar is attempting to do. They have a decent sized list of free channels, and soon will add an optional paid component. Users pay for their own dish, installation, etc. and only pay from then on if they want the optional package(s).
Also, if the economy was better, and they were able to secure funding, perhaps Equity could do something along these lines. As it is, sounds like they are just making it right now so I wouldn't want to suggest an expensive new venture.
ExpressVu has also proposed something like this in Canada (OTA networks delivered free via satellite) but I'm not sure it will get off the ground, because EV seems to expect the OTA broadcasters to chip in. However I think it would be a great way of providing coverage to the further northern reaches of Canada. Surely more economical than terrestrial means.