There's a slim chance he's still hiding somewhere in Afghanistan. There are also reports that he slipped into Pakistan and is being hidden there by Taliban supporters. There's also a possibility that he was blown to bits by a bomb, perhaps some time ago.

If he's still alive, the $25 million reward will likely cause someone to betray him sooner or later. If, and this is a pleasant thought, he was taken out by a bomb, we may never know for sure. If no word is heard from him in the next couple years, I'd be willing to bet he's dead. That's not exactly the closure I'd like but I don't see an alternative short of DNA testing on all of the body parts we can find in Afghanistan.