Disney wants Depp, according to the report, but timing is an issue, since Depp is already committed to making 'The Lone Ranger' (also for Disney) after finishing work on Tim Burton's 'Dark Shadows' this spring. Disney wants to start production on 'Oz' later this year.
For at least 30 years, this has been a major problem for the studios: Too many high-budget productions and too few stars available to star in them. They desperately yearn for blockbuster returns on franchise projects, but won't make them unless they have one of the "golden few," someone who can, in their minds, guarantee a minimum box office return. Does it really matter to you, the movie-going public, if Downey or Depp make the picture? Are they interchangeable at this point of their careers?
Here's another interesting angle: Earlier reports indicated that one of the key reasons that Raimi wanted to do 'Oz' was so that he could work with Downey. By now, he's probably invested months of his life into the project, and we're sure he'll see it through to the end, but Downey's dropping out still must feel like a kick in the head.
Of course, for all we know, Raimi and Downey talked about the movie, realized they had differing visions, and decided to part ways as friends.
And it's not like Raimi hasn't needed to replace a leading role before. Ellen Page dropped out of 'Drag Me to Hell' and that turned out just fine, with Alison Lohman stepping in for Page. Whoever ends up as The Man Who Would Be Wizard, Raimi's version should be spellbinding. We hope.