In September 2003, then-Secretary of State Colin Powell was reported to have identified Mrs. Plame as a CIA agent who convinced the agency to send her husband on a mission to Niger in 2002....Court papers filed by the defense suggest that Mr. Armitage leaked Mrs. Plame's identity to Mr. Novak and perhaps to The Washington Post's Bob Woodward.....Then-Undersecretary of State Marc Grossman was alleged to have told Mr. Libby of Mrs. Plame's employment at the CIA a month before her identity was leaked.

The lawyers' goal, according to the article, is to highlight the infighting among the White House, State Department and CIA over the flub over weapons of mass destructions.

"If the facts ultimately show that Mr. Armitage or someone else from the State Department was also Mr. Novak's primary source, then the State Department and certainly not Mr. Libby bears responsibility for the 'leak' that led to the public disclosure," the defense said in the March 17 filing.

Putting aside that Libby isn't charged with being the source of the leak but lying about where he learned the information and whom he told about it, that Fitzgerald will fight the introduction of this kind of evidence and it's up in the air as to whether the Court would allow it, Insight reports that Libby plans to subpoena Powell, Armitage, Grossman and Rove, and that "National Security Advisor Stephen Hadley has also been targeted by the defense."

Of course, bloggers and journalists reported this the day after the motion was filed (more here,