check out dish network. you can use one HD receiver for two rooms. you can use one HD DVR receiver for two rooms, and both can use the same DVR, but one room only gets SD (not HD). cutting down the lease fee for extra receivers helps out with the price.
plus, with comcast, you're paying about 15 bucks per DVR, right? i think it's only 7 with dish network. comcast will probably also give you a great deal when you call to say you're switching to satellite.