John Gruber:

Imagine watching a baseball game on a TV where ESPN is a smart app, not a dumb channel. When you’re watching a game, you could tell the TV to show you the career statistics for the current batter. You could ask the HBO app which other movies this actress has been in.

As usual Gruber has some nice thoughts on how a future Apple TV may work. Of course, you can also factor iCloud into the equation so content and apps (channels) would be available on multiple TVs.