Iron Man 2 is quickly turning into an A-List ensemble cast, with Mickey Rourke and Scarlett Johansson both confirmed to join Robert Downey Jr., Gwyneth Paltrow, and Samuel L. Jackson in the follow up to last years surprise hit.

Scarlett Johansson will play the Black Widow, a Russian spy. The role was originally going to Emily Blunt, who stepped aside due to her obligations to Gulliver’s Travels. A rep for Johansson said only that “Scarlett is thrilled to be a part of Iron Man.”

Mickey Rourke takes on the role of villian Whiplash. Fresh from his comeback in The Wrestler, Rourke is perfect for the role. The Whiplash character won’t be faithful to the comic series, instead being a combination of that character and the comic book character known as the Crimson Dynamo.

Iron Man 2 is slated for a May 2010 release.