Sienna Miller plays the Baroness, a sexy villain in the upcoming G.I. Joe movie, G.I. Joe: The Rise of Cobra. There's a lengthy description of the Baroness here on Wikipedia. Sienna looks curvier than we are used to seeing her so it has to be the sleek black outfit. The director of G.I. Joe has denied given Sienna rubber breasts to wear. A promotional trailer for the film is going to debut during the Super Bowl tomorrow. You can see a short teaser below. (via Just Jared)
