First there is a special prosecutor and if this ever goes to trial the very first thing he would do is put a CIA type on the stand to testify to Plame's status. Any prosecutor who at this stage of the game  who hasn't already reserched this basic element of the crime would be an idiot.  By now he would of announced the investigation has reveled no crime.

Second, in a decision againt Miller and Cooper a very sympathetic judge agreed with most of their arguments but stated that the seriousness of the crime was so great that he had to rule against them. This judge had access to most of the facts and he thinks there was a crime.

On the other hand an interesting point brought up by Abrams was that the person guilty of the crime is the person who crossed the bright line between people with a security clearance who knew Plame's ID and the rest of us.
If Rove did not have a security clearnce then the person who told Rove is guilty unless they didn't have clearance etc. etc.
Abrams said a common problem with former Governor presidents is that they have no national security experinece and then get in office and don't know that when they get a classified briefing they are not free to discuss it with just anyone.

Maybe Bush is the one who told Rove.