The media know who it is. If you read the Washington Post story carefully, the person who leaked to them, told them who the 2 leakers were, but refused to allow them to print the names. There are 2 journalists right there who know. The 6 including Novak who were originally peddled the story. At least several people at the White House including the W.P. leaker know. There must be several, otherwise, he couldn't leak anonymously, because the 2 on the CIA story would know right away who did it.
Many many people know who did it. They are hinting at Rove, without saying Rove because they can't do so.
All the stories you see filed by Washington Journalists, you have no idea which of them were part of the 6.