The only CBS programming I'm aware that is regularly prefed are the Saturday morning E/I shows. They started prefeeding that block earlier in the week because stations had gotten so irregular about their Saturday AM schedules.
Funny story about this...one Friday night several years ago, somebody at WTAJ forgot to shut off the national feed after Craig Ferguson, so anybody who was still up was treated to a black screen instead of whatever infomercial was supposed to be running. I kept it on just to see how long they'd go before somebody noticed...lo and behold, at 2:00, some show called The Doodlebops started airing. Evidently, at least at that point, they were feeding the Saturday morning lineup 23 minutes after The Late Late Show.
(And that's what we learned on the show tonight, Craig.)