We went to local HD programming with an OTA antenna and MythTV setup a few years ago and it has worked out just fine. Sure there were a few cable shows that were sacrificed. Guess what? Many could be viewed with various online options, and those that couldn't were gradually replaced by new 'favorites' from the available OTA signals. Not that it's entirely as much as a money saver as it should be. Comcrap in my market charges a PREMIUM RATE for internet only service (about 70-80 % of the rate for the basic Internet/TV bundles). They can see the writing on the walls, cable TV is doomed as a revenue stream, so they are shifting their pricing structures so that Internet access will be their primary cash cow in the future.
We actually added a very "limited basic" cable TV/Internet bundle back into our service this past year because the bundle saves $30 a month over Internet Only service. I did not let them reconnect all of the internal house wiring back to cable, which I had completely converted over to use the OTA antenna system. I only let them add the one outlet in the living room for cable. The cable service is provided from a deliberately crippled digital box that will only output in SD resolution unless we pay for additional upgraded service. But to be honest, since our OTA setup provides excellent HD programming, we don't care. The toddler happily watches SD cartoons on the cable box some times, and the rest of the time, we watch great HD programming on our own antenna system in every room in the house.
The MythTV setup allows TONS more HD recording capacity than any cable company provided DVR, with viewing options in every room in the house, plus the ability to start watching in one room and resume watching in another, multiple viewings of the same recordings in different rooms at the same time, and a whole host of other features. The cost of the OTA antenna setup, the MythTV backend, the hard drives for 3-5TB of storage, and muliple MythTV frontend machines was not inconsquential. But MythTV can use older hardware effectively enough that the entire cost of this switch over has been entirely recovered from the reduced cable bills. And it can be done in stages. The old cable system did not have access to DVR functions in every room, but evolution/expansion of the MytHTV system provides all of the functions that the previous cable company DVR system offered and much, much more, in every room in the house.
If/when they try to bump the rate on the Limited Basic cable/Internet bundle, we'll happily ditch the cable to go back to Internet only service. But as long as we can save money with the bundle ($300-400/yr) we'll keep signing up for a service we barely use. And the cable company gets to doctor their numbers to make it look like they are not losing as many cable tv subscribers as they really are losing to their stockholders