Word comes today that the secret to one of the great politico-journalistic mysteries has been revealed: the identity of Deep Throat. It was Mark Felt, assistant director of the Federal Bureau of Investigation during the Nixon administration. This is an important revelation, and not just to those of us who have followed the Watergate story from its very beginning. Watergate was the last great newspaper story, one that certainly would not have happened in the same way in our current media environment.