Rather than being disappointed in who Dumbledore turned out to be, I found it encouraging. Here is a hero who is not so different than any of us--one who has made choices, one choice which was devastating, but which set his feet and heart on a life-long path of redemption, as he tried to live the rest of his life as he now knew he should have done. The past could not be undone, as Dumbledore learned when he was once again tempted to try to use the Resurrection Stone, but except for that one last stumble, his choices for the future showed that he had learned from his mistakes, had taken responsibility for them, as he spent his life teaching students, being an example of mercy to all, and in the end, tried to help Severus and Harry accomplish what he, the greatest wizard of all, could not do--defeat the evil that terrorized the world in the form of Lord Voldemort. So even though Albus turned out not to be the perfect person many of us built him up to be, I think what Rowling gave us in Albus Dumbledore was much better.
Excellent piece. Go check it out!