Scarlett Johansson signed to play Black Widow in Iron Man 2 on Wednesday, according to Mark Malkin’s blog on E! Online.  The signing confirms rumors that began last month (see “ScarJo in Iron Man 2?”) when Emily Blunt, who was originally signed for the role, ran into a scheduling conflict.

The cast also includes Mickey Rourke and Samuel Jackson, in addition to Robert Downey Jr.