I do not believe that the bombings of Hiroshima and Nagasaki should be celebrated. And that does not mean that they are to be condemned either.
To each his own. As for me, I will celebrate the end of WWII!
This event, and this event alone, saved my fathers life. He had spent several months in training to lead a group of men onto the beaches in Japan before the bombs were dropped. I'm sure you'd feel different about it had you been drafted into the Pacific front.