There was never a crime committed for 2 reasons:
1. The leak was not intentional
2. The agent was not covert or undercover at the time.
Why accept the word of Powell-crony Armitage that the leak was unintentional? My guess is that it was very intentional and was designed to discredit Wilson in the wake of the Iraq invasion given Powell's reliance upon the Niger information during his appearance at the UN. It turned out that Wilson was lying and that he didn't need to be discredited; however, that was not necessarily known by Powell and Armitage at the time.
Also, it was not a single leak. Armitage "mistakenly" leaked info from the classfied State memo three times: 1) to Novak; 2) to Woodward; and 3) to an unnamed reporter. Finally, Armitage neglected to tell Fitzgerald about his Woodward conversation and did so only after having been prompted by Woodward. This is precisely the same kind of memory lapse that Fitzgerald is calling perjury on the part of Libby.
Really?
You mean the Washington Post got it all wrong?
I guess I won't be re-newing my subscription then. </sarc>