The answer that Wilson had when he returned from Nigera is more of a concern than the "outing" of his wife. I looks like someone gave him info that he had no way of knowing without help.
IMHO I think they are looking for serious (series) CIA leaks.
I agree that could be the case, but the fact remains, according to the CIA statement, Plame was a covert agent at the time of her outing...
Did you see the blood=thirsty bunch on the Chris Matthews show just now- they could hardly be any more thrilled over the possibilty of taking down Rove, etc.