Here's the salient facts that I've heard:
1. This Joe Wilson guy is a former ambassador, not a weapons inspector or WMD expert. He was a member of John Kerry's campaign and met with Kerry several times before going on his trip.
2. Wilson's wife was not a covert operative. She was working at a deskjob at the CIA, and when someone was needed to go to investigate the Iraqis seeking to buy yellowcake uranium from Niger, his wife suggested that Wilson get hired for the job... despite his lack of credentials to do the job.
3. Wilson goes to Niger, returns, and writes an op-ed piece that he was sent by Dick Cheney to investigate claims that the Iraqs had "bought" the uranium from Niger, and found those claims to be false, thus setting off the "Bush Lied" movement. What's important to note here is that the British, Bush, and the CIA all said that Iraq had been seeking to buy the Uranium, not that they had actually bought any. Further investigations have revealed that the Brits were right - Iraqi agents had tried to buy the uranium, and Niger nixed the deal. Wilson claimed in his article that Bush had said the Iraqis had bought uranium from Niger and that this wasn't true, nor was it true that Cheney had any knowledge of Chesney or his "mission". The only thing that Wilson said that was true was that the Iraqis had never bought uranium from Niger, which nobody ever said they had.
4. When the reporters started hitting Rove with questions about all of this, Rove tried to get them to back off the story because it was wrong. Cheney had nothing to do with Wilson, and no one had ever said that Niger had sold the uranium. He also told the reporters that it was Wilson's wife, who works at the CIA, who nominated him for that job.
5. Apparently Wilson's wife had at one time been a covert agent, but was no longer in that role. Also, it was common knowledge at the time that Wilson's wife worked at the CIA.
6. In order for a law to have been broken, a government representative must knowingly and purposefully use information that they are privy to, to expose a covert agent, working on foreign soil, or someone who has been in that position within the last five years. There's no indication that Rove knew anything or any more about Wilson's wife than anybody else did, i.e., that she was a WMD specialist at the CIA. Also, Rove did not mention Wilson's wife for the purpose of exposing her. He did it in order to show that it was not Cheney who initiated the trip to Niger, as Wilson had alledged.
7. In the end, you have a guy who's working hard to get John Kerry elected, who uses his wife's position at the CIA to get him into a position where he can make Bush look bad before the election, and who comes back from Niger and writes a bunch of bold-faced lies. If I were the special prosecutor, I wouldn't be looking at Rove, I would be looking at Wilson and his wife.
If Bruz's facts are correct, a) this seems like a non-issue to me, and b) I've never seen the facts printed by the media (that would be UFB).