Pakistan confirmed, via DNA tests, that their warplanes killed al Qaeda leader Muhsin Musa Matwalli Atwah, when a compound near the Afghan border was bombed last April. Atwah was believed to be the organizer of the 1998 bombings of U.S. embassies in Kenya and Tanzania. The U.S. has offered a $5 million reward for information leading to Atwah's arrest. Atwah was an Egyptian who operated an al Qaeda cell in Somalia in the early 1990s, and later traveled to Afghanistan, Pakistan and Sudan to receive training on bomb building.
Pakistan has killed or captured nearly a thousand foreign terrorists, or suspects, in the last five years. Getting confirmation of identities is often difficult, either because the body was blown apart, or there is no way, even with DNA testing, to confirm who they killed. The U.S. has gone to great efforts to obtain DNA data, often from kin, of suspected terrorists, so that suspects can be later identified, dead or alive.
Since 2001, most of the known al Qaeda leadership has been captured or killed. While data captured in Afghanistan during the 2001 campaign provided a lot of information on who the key al Qaeda people were, subsequent operations have provided a constant flow of new information (from captured data or interrogations.) So no matter how many al Qaeda leaders you get, there will always be more. But the new guys are often less talented, and less experienced. The quality of al Qaeda leadership has obviously suffered from all these losses. The widespread use of DNA testing has made it more difficult for terrorist leaders to use a popular ploy, faking their own deaths, so as to take the heat off them.