The Karl Rove/Valerie Plame issue is being thoroughly covered, but I can't resist weighing in.
First: Joe Wilson is a liar. He lied about the contents of his report, and he lied when he said he was recommended by Cheney and not his wife.
Second: The CIA didn't give a damn about Wilson's report, anyway. His only "qualifications" were an ambassadorship (a purely political appointment) and a wife who worked for the CIA. His report had little more credence with them than it would had I written it.
Third: It's only a crime to divulge the name of covert operatives. Plame was not a covert operative. Plame and Wilson had quite the penchant for posing for glamor photos for Vanity Fair, among others, though Plame dramatically would conceal her face beneath the shadow of a large hat, things like that. This is not the behavior of a covert operative.
Why did Rove name Plame? It's all right here, under the subtitle Telling the Truth.