At last month’s Hollywood Radio & Television Society luncheon, CBS Corp. CEO Leslie Moonves shared his philosophy on the best way to promote his company: “under-promise and over-deliver.” A sound strategy—and one that his company’s news division unfortunately failed to heed with the carnivalesque launch of the CBS Evening News With Katie Couric. After a splashy, multimillion-dollar media campaign that sent Couric on a much ballyhooed nationwide “listening tour” and put her face on the front of every bus in New York City, some 13.6 million curious viewers sampled her maiden newscast Sept. 5. But Evening News has been trending...