One current talking point gaining favor was that Fitz knew when he started his investigtation that Armitage--not Libby--was the source for the Novak column. Thus, the reasoning goes, Fitz should have never proceeded with the investigation. Not true.
Where did Armitage get the information he leaked to Novak about Plame? None other than our hero Scooter. So, contrary to what Brit Hume says, Libby--at Cheney's direction--was responsible for outing Plame.
David Corn of The Nation and Media Matters have done a superb job of puncturing right wing myths regarding the Plame leak case. One of these myths is that Armitage was independently responsible for the leak. This is what Corn writes:
The Armitage leak was not directly a part of the White House's fierce anti-Wilson crusade. But as Hubris notes, it was, in a way, linked to the White House effort, for Amitage had been sent a key memo about Wilson's trip that referred to his wife and her CIA connection, and this memo had been written, according to special counsel Patrick Fitzgerald, at the request of I. Lewis Scooter Libby, the vice president's chief of staff. Libby had asked for the memo because he was looking to protect his boss from the mounting criticism that Bush and Cheney had misrepresented the WMD intelligence to garner public support for the invasion of Iraq.
The memo included information on Valerie Wilson's role in a meeting at the CIA that led to her husband's trip. This critical memo was--as Hubris discloses--based on notes that were not accurate. (You're going to have to read the book for more on this.) But because of Libby's request, a memo did circulate among State Department officials, including Armitage, that briefly mentioned Wilson's wife.
Armitage's role aside, the public record is without question: senior White House aides wanted to use Valerie Wilson's CIA employment against her husband. Rove leaked the information to Cooper, and Libby confirmed Rove's leak to Cooper. Libby also disclosed information on Wilson's wife to New York Times reporter Judith Miller.
So, it is a complete lie to say that Libby was not responsible for the leak to Novak and for the Novak column. Scooter worked hard to get his "message" into the news stream--and accomplished that goal through the somewhat bumbling Armitage.