Bin Laden's face will not be shown for one main reason. It would prove beyond doubt that there was no attempt to bring this man to justice. A high calibre weapon was placed to his head and he was executed. He was unarmed, and with his wife and 12 year old daughter.
The devastation to his skull would show the brutality of his execution, and destroy any credibility to the idea that there had been any plan to bring Bin Laden to trial.
The trouble is, al-Quaeda thrives on martyrdom. They persuade several people each day to die, with the promise of eternal paradise. Death at the hands of the enemy is not a threat to their ideology. I believe that seeing Osama Bin Laden on trial in the Hague would have dealt a more crushing blow to the idea of violent fundamentalism that a bullet in the head ever could.
Obama knows that, yet did not have the courage to buck the trend of human history. We cannot glory in the trigger happy policy of an empire that has the gall to say 'that's not how we do things.'