Sonoma and fender4645 -
Comcast does have DVR rolled out and available to paying customers in at least several areas of northern Virginia and parts of New Jersey (from what I can tell) with the Scientific Atlanta cable box. And that's before 12/31.
It is a dual tuner but not HD.
Check it out www.comcast.com
and enter in 22301 for Alexandria, VA or 08002 for Cherry Hill, NJ.
22301 led me to this page http://www.comcast.com/dvrsa/
There's a demo, pricing and FAQ's on the site listed above
08002 led me to this page http://www.comcast.com/sadvr/
Looks like the service is live.