Mr. Trump’s administration is being assembled behind the scenes. But like much else in the nation’s capital, little stays secret for long. The list of names being mentioned as possibilities for crucial posts in Mr. Trump’s cabinet is growing by the hour, giving official Washington what it craves most: a never-ending parlor game as speculation grows about who might actually get the nod. A big revelation may come soon, according to Mr. Trump himself, who took to Twitter on Friday morning with some news. “Busy day planned in New York,” the president-elect said. “Will soon be making some very important...