There is a sleeper (waking?) witness on Bush & 9/11: Sibel Edmonds, a translator who alleges that she was bougt off witgh a promotion to keep silent about the adminstration ignoring evidence that suggested an attack was being planned. (I first blogged Ms. Edmonds in January. She's interesting.)
Salon has an article quoting Edmonds as saying,
Referring to the Homeland Security Department's color-coded warnings instituted in the wake of 9/11, the former translator, Sibel Edmonds, told Salon, “We should have had orange or red-type of alert in June or July of 2001. There was that much information available.” Edmonds is offended by the Bush White House claim that it lacked foreknowledge of the kind of attacks made by al-Qaida on 9/11. “Especially after reading National Security Advisor Condoleezza Rice [Washington Post Op-Ed on March 22] where she said, we had no specific information whatsoever of domestic threat or that they might use airplanes. That's an outrageous lie. And documents can prove it's a lie.”