It appears iCloud is starting to happen. iOS 4.3.3 firmware update for Apple TV went live a few minutes ago, and it quietly delivers some very cool features. The update adds support for the video hosting service Vimeo, which is cool, but here is the big wow: you can now buy TV shows through Apple TV, instead of just renting them.
Since the Apple TV has negligible built-in storage, when you purchase a TV show through the set-top box, it is presumably streaming to you from a cloud-based storage locker. Which is full of awesome.