Disney and Marvel have tapped Rebecca Hall (The Prestige) for the female lead of Iron Man 3.  The powers that be have moved quickly to initiate talks with Hall, as the previous frontrunner for the role, Jessica Chastain (The Tree of Life), turned them down only yesterday, citing scheduling issues.  All the better for Hall, who can prepare for her role as a "sexy scientist" who rivals Robert Downey Jr.'s Tony Stark in intelligence.  The third installment will feature the return of Downey Jr. after his scene-stealing turn in The Avengers, along with Gwyneth Paltrow and Don Cheadle.  Guy Pearce will join the fun and Sir Ben Kingsley is on board to play the villain.  Production on the Shane Black-directed Iron Man 3 starts this month in North Carolina before heading off to China en route to a May 3rd, 2013 release date.  Hit the jump for more on Hall's role and the overall plot of Iron Man 3.Variety reports that Hall is currently in talks with Disney/Marvel to play the role of a scientist who plays a pivotal part in the creation of nanotechnology known as Extremis.  The tech, which winds up in the hands of terrorists, is a carrier for a viral outbreak that causes considerable damage, especially to anyone who happens to be wearing a high-tech suit of battle armor.  The plot for Iron Man 3 will draw elements from the Warren Ellis' six-issue series, "Iron Man: Extremis." You can check out more about the rumored plot details here. Marvel declined to comment on the casting news, but I'm pretty sure that after turns in The Prestige, Frost/Nixon and The Town, Hall can handle the role of "sexy scientist." She's half-way there already.  Watch out Pepper Potts!