Here is Tivo's official quote, "A TiVo Digital Video Recorder (DVR) is designed to support standard definition television broadcasts. It will not support High Definition broadcasts. It is possible to connect your DVR to a High Definition television, and to some High Definition cable boxes or satellite receivers. However, the DVR will only record programs from standard definition channels, and all recordings will be displayed in standard definition. For more information on support for HDTV, please see When Will TiVo Support HDTV?"
notice the words, "some hi-def cable boxes" It is possible to go over to your local comcast outlet and talk to a tech and see if the S-Video outs will work -- because Tivo does have S-vidio inputs...mine, unfortunately didn't work.
One other option might be to use an RF splitter split with your coax cable and duplicate source from your cable box...one to the TV monitor, and one to the tivo box. But now you'd be getting into area that might make the setup unfriendly for your wife, because you'd have to change inputs at the TV side for each method of watching.
