Well, my DVDs of the first series of Soap and of E.R. have arrived from amazon.com. It is interesting to note that Soap season one was in 1977-8. Stylistically it is not very different from current TV comedy - there are certain echos of Friends in it, I would say - though Soap is funnier and less annoying. However, if we go back 25 years from 1978 rather than forward 25 we arrive at 1953 - which gives us the coronation and Muffin The Mule! It would seem fair to say that things changed rather more in the 25 years before Soap than the 25 after.
Another obscure item of trivia - one of the patients in the pilot of E.R. is Shiri Appleby, better known as 'Perky Waitress' in 'Aliens And Waitresses' (or to put it another way, Maria in Roswell).
We now are in the position of having TV 'too cheap to meter' in that we have hours of unwatched DVDs.