Name Change?

One of the things that stood out in today's New York Times article about Joe Wilson/Valerie Plame is that the article refers to her as Valerie Wilson throughout. I've run a google search to check whether they've ever done this before. As best I can tell, they haven't; they've referred to her consistently as Valerie Plame. Why the switch?

Could it be that they are trying to add credibility to their story that a State Department memo, rather than journalists, was the source of Rove's information? The blatantly obvious flaw in their previous story was that said State Department memo referred to her as Valerie Wilson, a name no one involved in this case has ever used to refer to her. How could Rove have learned the woman's name from this State Department memo, if the name he "outted" was Plame and the memo never uses that name?