A move to on-demand programming would probably stop me watching TV at all. I don't want to have to think what I'm going to watch all the time. If I can't stick the telly on and watch the current episode of Dr Who because it's on and have to go out of my way to choose to watch it...
Put it this way, when it's on at a certain time, I schedule things around it. When I have to choose when I watch it, it gets scheduled around other things. So if I have to choose, I've got a wholebuncha DVDs to watch already...