TiVoCasts were of course derived from podcasts, which I still adore, audio-only aspect and all. (Current fave? The Engadget podcast hosted by Josh Topolsky.) And I just learned that you can get and listen to all your favorite podcasts on your TV through TiVo's Podcaster feature.
This is great for me, since sometimes I forget to sync my iPhone or run out of "headphone time." Being able to play them on my TiVo is going to be a great convenience for me — hello, housecleaning soundtrack.