While I admit my enthusaism has dipped recently, the fact the film is now apparently ready to shoot is something I thought I would never see. Pulled from http://www.barsoomia.org/ (hope you don't mind) the film is set to begin production on January 28th at London's famous Pinewood Studios (the home of James Bond for you film geeks.) Pinewood's own site has a listing of the stages to be used and you can explore them here-http://www.pinewoodgroup.com/gen/z_sys_infoProduction.aspx?intProductionId=1907.
UPDATE: In a new interview, Willem Dafoe (promoting the vampire flick Daybreakers) says he is heading to London next week to begin filming. Well the sooner the better. For more of Dafoe's comments on playing Tars Tarkas-http://io9.com/5441944/willem-dafoe-gears-up-to-start-making-john-carter-next-week (and a special thanks to Mr. Tarkas for pointing out the article.)