I'm willing to bet that we anticipated this and had a plan for detaining or tracing terrorists. Our intelligence community may be "tagging" some of these guys in hope of following their communication and gaining information which will allow them to catch some big fish.
Letting the leadership slip out may be just the tip of the iceberg. (Sand Dune)
We know how their leaders operate. We know how to get into their communications. We also remove motivation for others them in jihad. When Haji (muslim Joe six pack) thinks about joining the great jihad and sees he has 0% chance of victory and 100% chance of defeat. The allure of jihad suddenly becomes very tarnished.
Constant failure marginalizes Islamofacist leadership.
Muslim troops are renown for throwing down their arms and going home. (Almost to the point of being French) Impending failure is a great rationale for surrender or desertion. When the enemy no longer want to fight, we win.
After 9/11 if we offed OBL right away he would of been a martyr inspiring thousands more martyrs in his name. Now he is nothing more than a loudmouth on the sidelines of a war he started. His capabilities consist of whining and thrashing around like a two year old having a temper tantrum. Strategically it may be a good thing OBL is still alive and a very public failure.
Keep your chins up. Zarquawi and OBL will be sharing a cave soon.
Keep the faith.