I believe Panasonic has discontinued support of CableCARD after their 2009 HDTV models. Certainly other manufacturers have done the same thing. That's a pretty good sign that you will not find much if anything in the newer HDTVs. The companies want us to continue to rent their boxes if possible.
Maybe poke around a little over at AVS forum for more of the gory details on that status of Cablecard.
Does anyone know if there are any new flat panel tv's (LCD, LED, or plasma) that are being made with a cablecard slot?