The development of on demand TV is expected to grow over the next few years, the biggest issue is capacity. In 2009 the amount of traffic generated each month by YouTube is now equivalent to the amount of traffic generated across the entire internet in all of 2000. Last guess that the infrastructure of the UK's web needs about £1 billion pound spent on it to keep up with demand.
Although this is the opposite way round from the thread title, I've used Iplayer on the Wii and surprising it works pretty well. Apart from Youtube and iplayer I don't really use any other sites, apart from the educational Redtube.
