This is supported by the rise of DVRs, allowing people to choose when they want to view their content without delving into the online realm of Hulu, Netflix, etc.
The problem right now is that none of the major online streamers have really good integration into any TV set. There also does not exist a good discovery system ("you like House? You might also like...") for anyone except Netflix, and they're more of a movie house than a television one.
In contrast, Netflix gives me a full HD video of exactly what I want to watch, when I want to watch it, with no ads. It's better even than a DVD, because the DVD forces me to sit through a bunch of copyright warnings, logos for the distributor, and half the time a main menu which wants to show me fifteen seconds of clips from the movie before I can press play.
As someone who recently moved from Time Warner Cable to U-Verse, U-Verse (which is an entirely multicasted IPTV system) is substantially faster than TWC in terms of channel acquisition speed — it's literally instantaneous. I suspect a lot of that has to do with Time Warner's increasing use of switched digital video rather than encrypted QAM, but that certainly isn't going to change anytime soon.
Caveats: (1) It's only for broadcast channels at this point; (2) it's unclear that what they do is legal, but they believe that it is and appear to be litigating this point.
Mark Cuban had a good piece on this subject a year ago, still rings true:
http://www.dmwmedia.com/news/2009/03/25/mrk-cuban:-cable-tv-...