According to Sci-Fi Wire, Andrew Stanton is working on a new draft of his script for the proposed movie (possibly a trilogy!) from Disney, not Pixar (since it's live-action and most likely at least PG-13), and they're starting to talk about casting. It would be interesting if Pixar were to at least handle the VFX, a logical next step from their all-CGI films, which have digital effects as complex as anything ILM or other 'live action' digital effects houses have created. I've never been all that confident in either a live-action or an all-CGI interpretation of the Barsoom universe, but with Stanton in there, hopefully as director as well as writer, I think this will finally happen, and they'll pull it off as a real ground-breaking film. Here's hoping!