Rebecca Hall is in talks to replace another rooooide in one of the lead female roles of Iron Man 3, says Variety.

The British actress will replace Jessica Chastain, who had to pass on the role of a "sexy scientist who rivals Robert Downey Jr.’s Tony Stark in intelligence" because of scheduling conflicts. Hall is pretty much signed up for the part, with Shane Black and Downey Jr. set to get cameras rolling fairly sharpish with the sequel - literally in the coming weeks. Hall is one of the most underrated actresses working at the moment; her work in the excellent indie comedy/drama Please Give is fantastic and... she's also very attractive. I interviewed her twice and we shared a moment - granted said moment was probably her waiting on the inappropriate staring to stop while Ben Affleck looked uncomfortable - but still... 

Anyhow, great casting; she's more than capable of keeping up with Downey Jr. and I really can't wait to see what Black does with the material.