True, but its hard to believe that despite incessently searching to determine who was behind the Africa stories, he conveniently "forgets" that his boss Cheney told him about Wilson and his wife. He forgets that two people at the CIA (one upper level and the other his briefing agent) both told him the same information. He forgets that the CIA faxed him a written statement concerning the identity of Wilson and the fact that his wife sent him to Africa. He forgot that an Assistant Secretary of State fed him the same information. Then he forgets that he discussed this information in six other meetings including one with Ari Fleischer, Press Secretary, a week prior to the conversation with Russert. Seems awfuly convenient that someone who is supposedly motivated to find out who is behind these stories about the 16 words and Africa, once they found out from numerous credible sources and discussed what to do about it with numerous other people would all of a sudden "forget" everything that had occured in the few weeks before hand. People with memory that bad would not be in top level positions in the White House.
The question isn't whether these governmental sources told Libby about Plame, but whether he had previously heard it from reporters or "in the wind," perhaps totally unconnected to the Niger story.