Just like the Apple Newton the first time, the world wasn't prepared, now the content providers are a dime a dozen, just bring in the apps. I would be writing this from my TV instead of my laptop and finally Facetime would be like in the Jetsons.
It's difficult to understate just how terrible attempting to use a computer on a tv screen is.
To me there's something very irritating about trying to focus on details (like a mouse pointer, or reading a page of text) from a distance. There's also the low PPI and size of tv screens; the viewing angle of the TV; the fact that your keyboard and mouse are sitting on your lap or whatever surface is near you (that's not at the proper height); that your chair/couch was designed for relaxing, and not sitting up and typing.
A small part of the could be fixed with a different UI.. but its still a bad experience.