Withits Sunday-morning news show This Week trailing third in the ratings, ABC has decided to reshuffle the decks and turn back the clock. Christiane Amanpour, the international-news reporter who took over the show in 2010, is returning to CNN to host an international-affairs show (while also reporting for ABC); and she’ll be replaced starting Jan. 8 by George Stephanopoulos, who hosted the show before her, and now will be doing double duty on Good Morning America.