Put the call into Comcast last week for two cable cards, and for them to pickup an older Digital Cable box. They showed up today with a single card and a digital box. It's Comcastic! *rolls eyes*
So after we got that sorted out, the installer guy put the two cards into the Series3 and things actually went pretty well thanks to Tivo's guide. It was the first time the guy had done one of the new CableCARD-enabled DVRs, but Comcast Customer Care seemed very well aware of it. (When I called to order two cards before, they cheerfully asked right away if I had one of the new Tivos.)
The only thing you lose, apparently, is On Demand. Pay-Per-View still works but only if you call the number… just like the olden days. Comcast blabs that you don't get their TV Guide (along with its ads, haha)… but you get Tivo's instead to replace it.
So far, so good.