Armitage (and the State Dept) was against going to war in Iraq. He would have a strong desire to bad mouth the CIA and the their intelligence. The CIA, while saying Wilson's trip to Niger did not provide anything new, they believed the trip actually supported the claim that Iraq pursued yellow cake in Niger. So while the Niger thing and Wilson's trip was in the news Armitage was mostly likely questioned about it by reporters (probably Woodward and Novak and others) he probably said to ignore Wilson's CIA Niger trip because Joe is a hack and his wife was the one who actually sent him.
I believe that Armitage was not trying to "get Joe", he was trying to "get the CIA" and discredit their intelligence claims.
I have no idea why Fitzgerald is ignoring Armitage's role in this whole Plame thing...especially since he was probably the first person to mention her to reporters.
"I have no idea why Fitzgerald is ignoring Armitage's role in this whole Plame thing...especially since he was probably the first person to mention her to reporters."
There is also the "how does novak fit in" question.