Novak said everyone will have a good laugh when he names his source.
Dick Clark would fit that description.
Bob Woodward would as well. Maybe Clark was Woodward's source and Woodward proceeded to blab the news around town. He stated he told Pincus.
We all know there are no secrets; once the word was out, it would have spread like wildfire.
Ari Fleischer?
Novak said he would speak when the investigation is over, but hasn't so far. Either he is waiting for Fitz to do his mop up work, or maybe he's expanding his revelations into an entire book. He knows everyone is waiting for him to speak, so he might try to milk this for a book deal rather than waste it all on one puny column that he'd be paid for as part of his regular syndication royalties.