Now that the second season of Downton Abbey on Masterpiece Classic has wrapped up, creator Julian Fellowes took time for a question-and-answer session with the New York Times in which he reveals a few of his fave American TV shows (Mad Man, Sex and the City, Glee) and addresses what all Downton fans are wondering: Just how long will the hit Edwardian costume drama keep going? “Sufficient unto the day,” Fellowes said, laughing. “I feel that one can’t really think much beyond that. Although I agree, I do not think it should just go on and on forever.”