While it took longer than it should have ashcroft has recused himself from the Valerie Plame leak investigation:

“The attorney general in an abundance of caution believed that his recusal was appropriate based on the totality of the circumstances and the facts and evidence developed at this stage of the investigation,” Comey said. “I agree with that judgment.”
Comey did not say exactly what evidence necessitated the recusal.

Hmmmm, the evidence might be just a wee bit interesting…..