Well, encoding technology today can provide for 4K via even modest download rate via internet, and the encoding tech in the future will improve so that 4K could be sent even via DBS sat efficiently, and new encoders are chump change for Dish and DirecTV, BUT, the real hard pill to swallow is that it will require hardware swap-outs of existing STB's at a big cost to Dish and DirecTV, and this may push DBS services further to the on-line delivery train. However, unless some of the content is allowed to be cached at the ISP so that everyone (larger numbers of users than today) doesn't try to pull down the same movie or TV show at the same time clogging up the backbone with identical requests, even the on-line streaming trend can hit bad bumps. Oh, and the data-caps issue, as well.
However, I do believe that the DBS services will still have satellites, but they may be used far differently than today. DirecTV and Dish could use sats to download the most popular requests efficiently and far faster than via internet with some services still part of a continuous digital stream as today. A good example of how this might work is DirecTV's Genie Start Over feature that while watching a sat channel, will grab the content you are watching from an on-line source and stream it from the beginning. Of course, there are limitations to the current DirecTV implementation, but that can be fixed in the near future. DBS Dish and DirecTV will probably turn into hybrid sat and on-line service.
Local ISP Caching would quickly become a nightmare for providers, unless there are cache pods like how the newsgroups have but they too just figure out routing. With these days of cloud bandwidth pricing, it should be possible.
On another note I believe the current receivers are software updatable if it requires a simple codec change. Unless the fundamental 8psk module changes.
In UAE, the cable content providers have all gone IP. They run a dedicated fiber optic cable to home which provides internet and cable TV. During the old days, they used to provide a dedicated copper cable to everyone’s house for DSL. Much more elaborate implementation there.