This is probably going to be the nail in the coffin for me to Cable TV in my house. I'll still be keeping cable internet but this is that last mile that I needed.
Is all of the content available to play through Apple TV? I was about to do the same (I have Hulu Plus via PS3) and noticed that most of the content that I watch wasn't available to stream on TV, only to the computer using the web browser player. You could, of course, run an HDMI from your computer to your TV, but that's not really ideal for me.