Bob, I believe the symptoms you describe below come from a situation dubbed by my friend Ty as "Tivopression." It's that nagging feeling that you've got a lot of interesting programming you'd like to watch on your DVR that you know you may never get to. Jeez, the season finale of The Shield is on this week and I'm still on episode 2. Nobody tell me what happened!
I just got the dual-tuner Comcast HD DVR and I must say (I had nothing to do with this when I was at Comcast, btw) it's pretty damn sweet. It rips off some of the ReplayTV UI features which I always liked better than TiVo, such as one-click recording while in a grid view. A red dot indicates the recording is scheduled. The dual-tuner thing is surprisingly useful. I never thought I'd need it, but you know how it is. And 15-hours of HD recording space (not sure if that estimate is accurate yet) brings a whole new level to Tivopression. I recorded a show on Beavers last night. Beavers. The kind that make dams in creeks.
As the amount of unique and special-interest programming balloons in availability over the next several years it will be interesting to see how our viewing habits change once again.