It’ll be interesting to watch how Apple’s iTV + iTunes competes with Tivo in the long run. The big difference is that iTV is inherently narrowcast — play podcasts and downloads from the iTunes store — while Tivo’s main schtick is to provide the advantage of narrowcast on top of a legacy broadcast video distribution system (cable).
Long-term I always bet on narrowcast, but there’s still a big question of timing: when does enough content become available on the Internet that you no longer need your cable TV subscription? And how much can Apple do to make that day come a little sooner?