The other problem is that there isn't a compelling consumer problem the Apple TV solves - whereas the iPod is orders of magnitude better than a CD player. I think that there's a good chance that Apple TV will be a dud. It will be a decent product but not a great product like iPod.
Anti-piracy technology like Audible Magic (free NY Times sub. req'd) is a huge friend of cable because the current cable business model (for programmers) is very profitable. The reason consumers shifted to digital downloads in the music world is because they could get stuff for free. If they can't, and piracy is really stopped, cable will continue to thrive and the alternatives will not be very good.
A friend recently relayed this anecdote:
*A note on the headline: Led Zeppelin's original name was going to be "The New Yardbirds," but when The Who's Keith Moon told Jimmy Page that "it would probably go over like a lead zeppelin," they changed the name to spite him. The letter "a" was dropped so that it wouldn't be pronounced "leed." (Rolling Stone)