From what I've read...
Rove didn't leak her name, he said, "his wife." If true, then it was someone else who looked up and released her name. Since Wilson's wife had a different last name, someone would've had to look it up. Nitpicking, admittedly, but the law if full of such nits.
The USA Today article suggests that the law about releasing her name may not have been broken, but suggests that if someone tried to cover it up, then there may still be a crime. Time will tell. That's what the grand jury is investigating.