CNN will begin to devote the 9 p.m. hour of prime time to new taped shows, starring Mike Rowe, Anthony Bourdain and others. The strategy is a shift away from the talk show format that CNN has featured at 9 p.m. for 30 years, first with "Larry King Live," then with "Piers Morgan Tonight." At 10 p.m., the cabler will offer rotating hosts in a new show called "CNN tonight," which addresses the day's biggest stories.