Huge move in the online content wars slipped out just now. Daringfireball's John Gruber reports a software upgrade to his Apple TV is allowing him to watch any TV show he has previously purchased in iTunes via Internet streaming on his Apple TV. Previously, you could only rent TV shows via iTunes on your Apple TV. Purchased shows could be watched on computers and iOS devices but not Apple TV.
Apple is already the only big player that licensed the rights to stream previously purchased music from the music labels but it lagged behind Amazon streaming of previously purchased video (via Amazon video we can watch on the web or download to our TV any show or movie we've previously purchased any time we'd like).