This seems to be a hot topic lately...
I don't know of this being available as it would render cable / dish services useless and I don't know if you are aware of this but in many cases these services go hand in hand. There's a 50% chance that you have cable internet at home right now. The reason I say that is because if cable services were broadcast over the internet in real time the cable companies would have to have something in it and I can't see them trying to put themselves out of business.
I too would like to ditch the dish and go all internet but I just don't see that happening. Not any time soon, anyway.
There are various services you can take advantage of (Hulu) but nothing live / real time.