When was he accused before? I truly don't recall.
He was the first one pointed to before it became clear he didn't do it and attention turned to Scooter Libby, where it stayed until finally reporters were forced to admit Libby didn't do it, either (both Libby and Rove signed waivers long long ago allowing reporters to disclose the content of their discussions).
Here is how the ball got rolling on this trumped-up "scandal"---with Wilson himself pointing to Rove:
Did Rove Blow a Spook's Cover?
Sept. 16, 2003
The question of whether to investigate who in the Bush administration blew Plame's cover surfaced Aug. 21 at a forum about intelligence failures on Iraq held by Rep. Jay Inslee, a fervently anti-war Democrat. Wilson, who was present, had this to say:
It's of keen interest to me to see whether or not we can get Karl Rove frog-marched out of the White House in handcuffs. And trust me, when I use that name, I measure my words.
This appeared to be an unsubtle hint that Wilson knew one of the leakers to be Rove. Taking the bait, someone asked White House press spokesman Scott McClellan about it today:
~snip~
Then see adam's post at #92. When push came to shove, Wilson backed off the Rove accusation.
Rove will be in Cooper's notes, but not as a source (impossible) for revealing that Plame recommended Wilson for the Niger trip.