I don't know that celebrate is the word I would choose to say we are not mourning the death of a man that devistated our land. I think it better to say that we are relieved and yes, happy that he is no longer here to threaten us. However, I also do not feel the "threat" is gone. I would lean more towards the thoughts that retaliation is probably not far behind for us. We would react no differently.
In a more direct answer to this question... let us have our moment. Many lives have fallen because of this man. Families will set one or two less plate on their dinner table because their brave father, son, daughter, friend gave their life to find this man and stop his terror reign. I say God bless our brave men and woman. As for Osama Bin Laden... Let him and God settle it.