Karl Rove One: I never disclosed Valerie Plame's identity.
Karl Rove Two: I never disclosed Valerie Plame's name
Karl Rove Three: I first heard it from a reporter, I can't remember which one.

Karl Rove's current version in today's New York Times:

People who have been briefed on the case said the White House officials, Karl Rove and I. Lewis Libby, were helping prepare what became the administration's primary response to criticism that a flawed phrase about the nuclear materials in Africa had been in Mr. Bush's State of the Union address six months earlier.

They had exchanged e-mail correspondence and drafts of a proposed statement by George J. Tenet, then the director of central intelligence, to explain how the disputed wording had gotten into the address. Mr. Rove, the president's political strategist, and Mr. Libby, the chief of staff for Vice President Dick Cheney, coordinated their efforts with Stephen J. Hadley, then the deputy national security adviser, who was in turn consulting with Mr. Tenet.