If I understood Brit Hume correctly, I think Novak DID reveal his primary source.
http://www.freerepublic.com/focus/f-news/1663955/posts
When Fitzgerald arrived, he had a third waiver in hand -- from Bill Harlow, the CIA public information officer who was my CIA source for the column confirming Mrs. Wilson's identity. I answered questions using the names of Rove, Harlow and my primary source.