You don't think he'd talk do you? Nope. You'd have quite a time getting anything from Usama. He'd welcome becoming a martyr for his faith and his cause. He ain't talkin'. As far as you or I or the rest of the world would know...he's dead.
You're only a "martyr" if others know you are not talking. No one will ever know and no one will ever hear from OBL again.
Now, that doesn't mean we can't actually keep him for as long as it takes to extract the information we need.
If he's caught, I have a feeling he won't live long. He's wanted dead or alive and I don't believe anyone's going to take any chances of his getting away with this.