According to a link I discovered through Original Edition Fantasy, Andrew Stanton's live-action John Carter of Mars film begins shooting next January, with a 2012 release date. Principal casting is now complete, with two actors I've never heard of starring as John Carter and Dejah Thoris, Taylor Kitsch and Lynn Collins respectively, with Willem Dafoe as Tars Tarkas (presumably just his voice, since I suspect he'll be a CGI character).
I learned long ago not to make any determinations about a film based solely on its casting, since, more times than I can recall, seemingly bizarre cast choices worked brilliantly while seemingly perfect ones proved less than ideal. Consequently, I continue to remain hopeful that Stanton has what it takes to bring Barsoom to the big screen in a way that's true to the novels. He's made a lot of the right noises in various interviews I've read, but, of course, this is a Hollywood production, so anything is possible, especially completely failing to miss the point of the original Burroughs stories.