There is one aspect of the Valerie Plame spy or not spy game that has actually not been discussed enough. If she was a covert operative at the time she arranged for Joe to conduct high-level tea drinking operations in Niger, then she and anyone in her chain of command was horrendously negligent in putting her cover at risk. Let's think about that for a minute.
A case officer or covert operative has an identity that they use for intelligence operations. They have a responsibility to maintain the secrecy of that identity and to maintain a low profile so as not to draw undue attention to it. This responsibility is paramount in the success of such an agent. Care must be taken not to expose their identity, but also to ensure that none of the contacts or assets they interact with will be exposed either.
Joe Wilson had no special qualifications that would recommend him for this trip and by volunteering him Ms. Plame and anyone in her chain who approved this trip made glaring errors perhaps even firing offenses. Even worse is the Op-Ed he wrote for the NY Times. Ms. Plame would have had an obligation top tell him to zip it, were she actually covert. There is now way on earth you could rightly say that his publishing a piece calling the President of the United States a liar wouldn't generate undue publicity. None of this would excuse someone if they purposely revealed her name knowing she was covert, but we know that didn't happen. Nobody involved knew she was covert, and if she was, she was either near-criminally incompetent or she simply was not covert.
Armed Liberal over at Winds of Change has a piece examining the law and some statements about Ms. Plame that's kinda interesting.