I have Tivo, and love Tivo. Everyone will eventually have a DVR of some sort, and eventually they will all be as nice to use as Tivo is (common sense and better hardware will see to it).
But they aren’t yet, in fact, every cable-provider-provided DVR I’ve ever seen or heard of is just terrible. UIs are unintuitive, features are missing and responsiveness leaves much to be desired (to put it mildly).
So, while I have seen (and drooled over) HD broadcasts, the benefits of the Tivo lifestyle far outweigh the benefits of crystal-clear HD TV shows. I can wait until Tivo puts out their own HD hardware.