http://blog.reelloop.com/12186/news/...-the-avengers/

Norton played Dr. Bruce Banner in director Louis Letterier’s “reboot” of The Incredible Hulk in 2008, and would have joined the already-cast Robert Downey Jr. (Iron Man) Chris Evans (Captain America), Chris Hemsworth (Thor) and Samuel L. Jackson (Nick Fury) in The Avengers. Apparently, though, the folks at Marvel think he’s too difficult to work with again.