The betting is that Kristoff received much of his information in this article from Judith Miller who very likely knew Plame. I am not sure that Kristoff has appeared before the Grand Jury (probably not), but I would grab the SOB and put him in a cell next to Miller.
I think the Republican Senators ought to pass a law that restricts spouses from being in the same branch or same type of work for the federal government. ANYTHING that smacks of conflict of interest or favoritism or nepotism (which I think definitely went on in the Niger business) should not be allowed. Look at Linda and Tom Daschle's cozy arrangement - she worked as a special interest lobbyist and you know she influenced Tom while he was majority leader. The whole thing is disgusting!