I dont think he has been the head of Al-Qieda (sp) for a number of years so not a case of anyone filling his boots, thats already been sorted. And regarding keeping him alive, there would be no way anyone could do that. For one thing he would never give any information, and if America did hold him then there would be hundreds of Westerners kidnapped around the world in retaliation.
I cant say I believe 100% that this is all true, but then anything within the media is generally only 50/50