Many digital cable systems have that in place. DISH Network satellite has a personal video recorder receiver, and DirecTV satellite has a TIVO unit.
Yeah, back east they have some options like HBO on demand, you can watch any HBO production ever made and some of them are quite good. Oz, Larry Sanders, Dream On and of course Sopranos, etc. I can't get that here in LA with my crapola Adelphia cable package which is why I just went and bought my own DVRs. I don't want to be at their mercy anyway. By they time they roll it out here, I will already have 1000's of titles saved on my computer - almost entirely automatically. I just pick what I want to record, and the computer automatically backs it up onto hard drive space. It's my own video on demand system.