OK, How would it work? Does it just have a little IR thingie that sits in front of the digital cable box? So you'd use the Tivo to control the cable box completely and shelf the cable remote? Not that that's a big deal, so long as it works.

Yes, it comes with 2 IR transmitters (because ReplayTV units can control 2 seperate input sources) that stick to the unit you want to control. I have mine attached to the front of the Dish 301 box, and it has never failed to change a channel to record something. The only time I would need the Dish remote would be to either check my signal strength, or buy pay per view shows.