Glenn Reynolds has a chunk of links at Instapundit.com regarding the Niger unranium issue. Between this, Iraqi WMD, the Sudanese aspirin factory, and let's not forget the Chinese Embassy in Sarajevo being mistakenly targetted in that war, the CIA's credibility is currently zero. At this point, I wouldn't trust them for directions to the men's room.
The immediate problem: we as the US have no means left to gather intelligence that can be considered reliable. The CIA is supposed to be the eyes and ears of our foreign policy, and a person that can not trust his eyes is as good as blind.