Hollywood Reporter says:
Robert Downey Jr. has fallen out of Oz, the Great and Powerful, Disney’s prequel-ish take on The Wizard of Oz tale, and the studio is in discussions with Johnny Depp to step into the great wizard’s robe.
Sam Raimi is due to direct the tale of Oz as a young illusionist with a grandiose attitude who is forced to flee a traveling circus. His hot air balloon is swept up by a tornado to the land of Oz, which is run by two magical wicked witches.
I actually don't know how to take this news. One one hand Johnny Depp is fantastic and it's possible and highly probably he'll be great in the role and could even come up with yet another beloved character that creates a new Wizard franchise.
On the other hand, RDJ is an incredible actor in his own right and he's shown he can take interesting roles and make them his own thereby creating himself another recurring role as a fascinating character.
Either way I think we win I'm just not sure who I'd like to see in the role.
Id say this would be a common sense move if at all plausible for the studio and team. Johnny Depp is a tremendous actor, and when you throw him into these roles he just steps it up even further. I dont know if he really is twisted or what, but he is perfect for these roles and no one can do it better.
Downey would be more of a namebrand than anything, so switching him out would be a good idea.