This makes more sense
If the outing of Valerie Plame only occured as a means to silence her husband, Joseph Wilson, from making the administration look like a bunch of incompetent liars, it failed.
However, this reason? It makes a bit more sense:
According to current and former intelligence officials, Plame Wilson, who worked on the clandestine side of the CIA in the Directorate of Operations as a non-official cover (NOC) officer, was part of an operation tracking distribution and acquisition of weapons of mass destruction technology to and from Iran.
Ah-ha. Now it becomes clear. Lets shut up a source on Iran, one who would surely rebut your contention that Iran is say, 5 minutes away from exploding a nuke at Disneyland.
Say what you will about these folks, they certainly plan ahead.