I'm actually beginning to look at internet streaming options. It may not be the best solution for RVing at this time but it seems to get better every year.
At home with our DSL service we've begun using Netflix, HULU plus, HBO Go and a Sony Streaming device. I can get just about any TV show and movie that I want to watch. It may not be in real time but within a month of broadcast.
Most stations now have website where you can watch shows as well.
I'm guessing that within 5 years between a good high def digital antenna to get the local channels, an internet streaming device and internet connection (including WiFi at a campground) you'll be able to get all of the programming you'll want.
Netflix is $8 per month and some of the others have fees but most of the broadcast network website content is free.
I have Dish now with the full package minus sports and pay $139 per month....not for long if the internet streaming continues to improve.