How do you know that the body could be produced? Did Ike produce Hitler's body at the end of World War II? If not, why not? What is the disposition of human remains after a 15,000 lb "Daisy Cutter" is exploded at the entrance to a deep cave, typically? And, how exactly would we be in better shape if we produced Osama's body? Would that increase or decrease his prestige among Muslims, vis a vis the current situation where he has simply disappeared, and his spokespeople are forced to make up e-mails on his behalf or release old "greatest hits" videos? And how would producing Osama's body further stiffen US resolve to continue the war on terrorism, exactly?
At any rate, producing a body would give the American people some confidence in how their government is 'protecting them' and how it is prosecuting the criminal terrorist. To assume the Prince is dead when you dont know, is about as productive as assuming the North Koreans will not develop Nukes just because they have signed a treaty.