One of the biggest surprises on Broadway this season was the box office success of “Doubt.” “In the surprisingly brief space of four months, “Doubt,” by playwright and “Moonstruck” screenwriter John Patrick Shanley, is in the black, a condition that most Broadway productions never achieve. In mid-June, its producers announced the play had made back the $2 million spent to get it to Broadway. Now their talk is about how best to widen “Doubt’s” reach. Plans are already in the works for a national tour — another rarity for a non-musical. A London run, naturally, is being discussed, and there’s early buzz about a movie.”