Ben Smith generates attention anywhere he goes. See: Politico, BuzzFeed, and the New York Times, where his appointment as media columnist and his departure less than two years later were treated as Significant News by the paper of record itself. Now he has the gaze of the media world again with the launch of Semafor, the digital news operation he co-founded with Justin Smith, a veteran publisher who was most recently at Bloomberg. For much of the last year the two Smiths (they are unrelated) have dropped all kinds of hints about what they were doing without really explaining what...