One variation of the "no crime was committed" argument going around is that Rove didn't really out Valerie Plame because he never mentioned her name to Cooper. Here is the text of the law in question:
50 USC 421(b)
Whoever, as a result of having authorized access to classified information, learns the identity of a covert agent and intentionally discloses any information identifying such covert agent to any individual not authorized to receive classified information, knowing that the information disclosed so identifies such covert agent and that the United States is taking affirmative measures to conceal such covert agent’s intelligence relationship to the United States, shall be fined not more than $25,000 or imprisoned not more than five years, or both.
The key phrase for this argument is "discloses any information identifying such covert agent." It does not say "gives away the name of the covert agent."
Imagine I'm sitting in a cafe in Istanbul, sipping thick, sweet coffee with an al Qaida agent (he's under cover, of course. I never knowingly break coffee with such people). Valerie Plame walks in and I say, "See that lady in the blue dress? That's Ambassador Wilson's wife. She's a covert counter-proliferation specialist for the CIA." Do you honestly think I would have a chance trying to argue in court that I didn't blow here cover because I never mentioned her name? Do you think I would have an ethical leg to stand on if I claimed I bore no responsibility for the damage done to her program by her exposure?