It answers the question: "Why would anyone in their right mind working for the White House have told the CIA to send Joe Wilson on a sensitive mission?" Answer --"Nobody did. His wife got him the gig."
She should have been fired for giving Joe the gig, but it was evidently just hunky-dory with her bosses. When you add the fact that the criminal referal came from... Plames Big Boss at CIA... you have what you have — a CIA run operation to embarrass the chief executive.