For nearly the entire time of his investigation, Fitzgerald knew -- independent of me -- the identity of the sources I used in my column of July 14, 2003..... Some journalists have badgered me to disclose my role in the case, even demanding I reveal my sources -- identified in the column as two senior Bush administration officials and an unspecified CIA source. I have promised to discuss my role in the investigation when permitted by the prosecution, and I do so now.

Fitz had waivers from all three of his sources:

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.

He later testified to the grand jury. He explains why he revealed Rove and the CIA's Bill Harlow as two of his three sources:

I have revealed Rove's name because his attorney has divulged the substance of our conversation, though in a form different from my recollection. I have revealed Harlow's name because he has publicly disclosed his version of our conversation, which also differs from my recollection. My primary source has not come forward to identify himself.

He sticks to the "non-partisan gunslinger" story.

In my sworn testimony, I said what I have contended in my columns and on television: Joe Wilson's wife's role in instituting her husband's mission was revealed to me in the middle of a long interview with an official who I have previously said was not a political gunslinger. After the federal investigation was announced, he told me through a third party that the disclosure was inadvertent on his part.

Following my interview with the primary source, I sought out the second administration official and the CIA spokesman for confirmation. I learned Valerie Plame's name from Joe Wilson's entry in "Who's Who in America." I considered his wife's role in initiating Wilson's mission, later confirmed by the Senate Intelligence Committee, to be a previously undisclosed part of an important news story. I reported it on that basis.

So his source for Plame's name according to him is Who's Who. Who's the primary source? He's not saying. A non-partisan gunslinger who disclosed it inadvertantly. Sounds just like Bob Woodward's source. And that source has talked to Fitzgerald and 'fessed up his role and is now referred to by Fitz as an "innocent accused." Richard Armitage seems the most likely to me.

Update: Howard Kurtz has more at the Washington Post.