They started principal photography already. There's no real plot being released but it is said that it will include the Mandarin (who apparently is being played by Ben Kingsley... dunno how I feel about that), the A.I.M. terrorist organization, The Extremis virus (they cast Guy Pearce as Aldrich Killian, and Maya Hansen's in it too), the Iron Patriot/Coldblood (Eric Savin), and Firepower (some other villian dude named Jack Taggart out to kill Tony Stark). Don't ask me how the hell they're gonna fit all this shit into one movie.

http://www.imdb.com/title/tt1300854/