that Mandarin is indeed playing a part in the film? I mean it is comicbookmovie.com so....
...The site also claims that a source "involved with the production" reassured them that The Mandarin is "definitely" the villain. He said Mandarin had a set of twins that did most of his dirty work for him. Another source who had visited EUE/Screen Gems Studios told us that the sets they were building included Chinese storefronts."
I believe we all would want Mandarin. It's Iron Man's Green Goblin, his Joker so to not have the character appear during IM's big coming out trilogy would seem a crime.
I'm guessing, if true, they are saving the official announcement for a big event. Say July Comic Con or NY Comic Con to parade out RDJ and Kingsley then show some footage.