TV news is suddenly crowded with 20-something models who stumble on words with more than three syllables and are never quite sure if famine in Bangladesh is happy news or sad. Tracy Rowlett reassures precisely because the years have bequested him with the opposite set of traits--some wrinkles, some schnozz, a bit of jowl and a dead-on news sense. When Rowlett relates a major story, we can tell that he himself knows what the story is about. We trust him never to announce with an engaging smile that Washington is under attack.