Sequel we didn't get to see
Before Christopher Nolan rebooted the 'Batman' franchise, Warner Bros were keen to make a fifth Caped Crusader adventure. George Clooney and Chris O'Donnell were to play Batman and Robin again, with Jeff Goldblum attached to play the villainous Scarecrow. However, following the backlash against Joel Schumacher's 'Batman & Robin' the idea was quickly shelved.While it would have been great to see Goldblum in that universe, a third Schumacher 'Batman' film would have been three too many. There is a reason fans ask, 'Who is Batman's biggest villain - The Joker, Riddler, Penguin or Schumacher?'
http://uk.movies.yahoo.com/blog/article/62766/sequels-we-didnt-get-to-see.html