Christopher Nolan (and co-writer David S. Goyer) have commented before that if Heath Ledger hadn't tragically died that The Joker character would have almost certainly had a small role or a cameo in The Dark Knight Rises. Hypothetically, what do you think the role/cameo would have been if Heath hadn't of died and Joker made an appearance? The Joker being put on trial for his crimes? Him being executed in prison? Batman visiting him in Arkham Asylum for some reason? Maybe him breaking out of prison or Arkham Asylum and being the main villain again? Etc., etc.