Marvel Studios and director Shane Black are prepping up to get Iron Man 3 into production, and they are looking at casting Jessica Chastain (The Help, Take Shelter, Tree of Life) to star opposite Robert Downey Jr. in the film. According to Deadline, she would play "a sexy scientist every bit as smart as Tony Stark."
This is actually the second time she's been up for this role. She was actually offered the role at one point, but had to drop out due to a scheduling conflict. After she dropped out Marvel met with other actresses such as Diane Kruger, Gemma Arterton and Isla Fisher. It looks like Chastain's schedule has opened back up and Marvel still wants to cast her in the role, and this time it looks like she's going to take it.
Chastain is a wonderful actress who's going to be a great addition to the third film in the Iron Man franchise. She will also join Gwyneth Paltrow, Don Cheadle, Scarlett Johansson, Guy Pearce and Ben Kingsley in the movie. As previously reported this next chapter in the franchise will follow the Extremis storyline from the comics. I have no doubt that we're going to get yet another incredible Iron Man film.