Odds are, you're going to be getting it through your computer. Whether it's Hulu.com, Netflix, another Internet subscription or a la carte payment per show through the networks themselves, your computer is going to be your hub for televised entertainment.
So, you could route your computer to display the picture on your HD TV, but that expensive TV is now just serving as a monitor. There's no real need for most of the costly electronic components that come with it. Your computer is serving that purpose.
You just need a rectangle. So wouldn't hooking an HD projector up to your computer mean a much bigger picture for a much lower investment?