The scary-toothed Mandy Grunewald, Hillary chum extraordinaire, could very well have been the person who tipped her husband off. She would have known Wilson's wife's profession...heck, they probably all went to the same cocktail parties.
I didn't think of this last night. (duh)
I have followed this story but it never stuck in my mind (I can't remember if I saw it before) that Matt Cooper was involved, although I knew full well who his wife is. It didn't click when I read this last night, but I think you're on to something.
It is outright laughable, IMO, this notion that's given out that Plame's "name" (they mean profession) was "leaked" to "ruin" Joe Wilson. It has always been obvious it was given by way of explanation for the outrageousness that he would ostensibly sent on any mission on behalf of an administration he blatantly despised. The "ruin/leak" story the was given out later just for the spite and political machinations of it all.
A Wilson/Plamegate thread is not complete without my noting that I hope and pray this grand jury indicts this duo--Joe Wilson and Valerie Plame.