The al Qaeda members rarely had precise information on specific attacks. That's because al Qaeda doesn't control terrorist operations by it's members, instead, al Qaeda ("the Base," in Arabic) supplies technical and financial support without knowing all the details. This drives intelligence agencies nuts, because there is no central headquarters where secrets can be stolen from, and operations quickly compromised. But in addition to captured al Qaeda staff, the events of September 11, 2001 have suddenly made many nations more cooperative in dealing with terrorist activity. Many nations, especially in Europe, allow terrorist organizations to operate as long as they don't do anything nasty locally. This arrangement has existed, unofficially and without any fanfare, for decades. Al Qaeda went over the line, and now many of these foreign police and intelligence agencies are rounding up people they have long suspected of running terrorist operations. Many of the people picked up turned out to have al Qaeda connections, even if their main allegiance was to some other terrorist organization.
All this new activity and cooperation doesn't always work. The suicide boat attack on a French tanker off Yemen and bombing in Bali last month all were know, in general terms, to be in the works. But the Yemeni and Indonesian governments were not as enthusiastic about rounding up local terrorists, and the attacks succeeded. Moreover, al Qaeda is adapting to the new scrutiny and making more effort to hide their tracks. How successful they are will be seen in the next year by the number of attacks they can pull off.
Normally, the CIA does not take credit for successful operations. Despite the benefit of letting people know the agency is doing it's job, announcing this sort of thing risks exposing agents and methods that are needed for future work. But the war on terror is being fought more in the open, and one way to defeat terror is to show the terrorized that the bad guys are being defeated. With that in mind, the CIA has announced numerous terrorist operations it has derailed in the past year or so. For example, there were three attempts to kidnap American officials overseas, as well as several planned attacks on American embassies and military bases in Europe. All were thwarted because of information obtained from captured al Qaeda members, and police work by European governments.