CBS has tapped its top sports exec, Sean McManus, to tackle double duty and replace Andrew Heyward as head of the network's news division, effective Nov. 7  the day before the release of axed producer Mary Mapes' book about her and Dan Rather's suspect reporting on President Bush's military service. "There was a general feeling that we needed a new vision, a new way of looking at the news division," CBS chief Les Moonves said in the announcement.