You ask: "Could someone please how anyone could be indicted for 'outing' Plame when her husband (Wilson) bragged about his 'secret agent' wife on his web page some years ago?"
I don't believe that it was claimed that Wilson stated on his web page that she worked for the CIA or as a secret agent there -- only that he listed her maiden name. (See http://www.opinionjournal.com/forms/printThis.html?id=110004094)
I honestly don't think that is what protecting covert status is about. Assuming she was covert, it wasn't her maiden name that was secret. (Someone could get that by doing various sorts of background checking, I think.)
The bigger question, it seems to me, is who first publicly stated that she worked for the CIA (as a secret agent)? If she wasn't really covert, maybe none of this matters. But if she was, then the question is who blew her covert status -- not who blabbed about her maiden name (which would be known to a lot of people, and pretty easily found out).
As has been said a million times, a prosecutor can indict a ham sandwich. The question is can Rove be convicted, or will he have to plead out just to get this off the President's head, or will Bush pull an Ernie Fletcher and just pardon everyone?