That “tick tick tick” heard in the hallways at CBS News isn’t the “60 Minutes” clock—or Walter Cronkite’s pacemaker. It’s the Countdown to Katie, suspenseful buildup to the monumental moment on Tuesday, Sept. 5, when Katie Couric takes over the “CBS Evening News.” And what are people saying? What are they talking about? They’re wondering if she’s going to wear slacks. They’re asking if her legs are going to show. They’re even debating whether the anchor desk will be made of plexiglass so that we can all play peekaboo through it. “Nobody asked those kinds of questions when Brokaw started...