Ledger totally deserved it. His death may have guaranteed him the win, there is no way to prove otherwise (just as there is no way to prove that it did). The fact remains that it was a stellar performance. Ledger brought something new and interesting to a character that's nearly seventy years old. It's kind of tiring to hear all the naysayers complaining that the only reason people loved him in the role is because he died. That's a cheap shot, and is unfounded. His death did not make any of his old work any better, yet I still wish I could see him in another Batman movie.