This time they're serious. CNN's prime-time anchors, Paula Zahn and Anderson Cooper, officially launch their new shows Monday. Yes, they've both been on the air for months, but the Atlanta network is repackaging them in a bid to boost sagging prime-time ratings. "There is going to be a structure to the hour," producer Jim Miller said of Zahn's retooled show. "Viewers are going to understand the show in a way they couldn't this summer." Anderson Cooper's show will air at 7 p.m., followed by Paula Zahn's at 8. Zahn's straight news program will be called "Paula Zahn Now." Cooper's show,...