As impressed as I was by the cast of Iron Man – you’d normally expect Robert Downey Jr., Gwyneth Paltrow, Jeff Bridges and Terrence Howard to be gracing a gritty and grim Sundance programmer – director Jon Favreau seems even more determined to raise the acting stakes for his forthcoming sequel, Iron Man 2: Extremis Boogaloo (ok, I made that last bit up).

It’s already been confirmed that Mickey Rourke and Sam Rockwell are in talks to play the movie’s villains, Crimson Dynamo and Justin ‘MC’ Hammer, while Don Cheadle has replaced Howard as Jim Rhodes as well as a possible replacement for Sam Jackson’s Nick Fury. And now it looks like Favreau may have found the perfect actress to fill the catsuit of the alluring Soviet superheroine, The Black Widow: our very own Emily Blunt.

Blunt’s participation as The Black Widow – aka Russian spy Natasha Romanoff – hasn’t been confirmed by Marvel yet, but it looks like it could well be a done deal. If so, it caps off Blunt’s meteoric rise, which began with stealing scenes aplenty in The Devil Wears Prada and Charlie Wilson’s War, and now includes a lead role in the forthcoming The Wolfman.

The script for Iron Man 2 is still being thrashed out by Justin Theroux, so it’s not known if Romanoff will be a hero or villain in the movie. Traditionally, she’s a hero, although her first appearance saw her assigned to seduce Tony Stark and kill his alter-ego, Iron Man. And, given that Crimson Dynamo is also Russian, expect her to be involved with Rourke’s character some way. But we’d be staggered if Romanoff didn’t generate some out-of-uniform heat with Downey’s Tony Stark, much to the chagrin of Paltrow’s returning Pepper Potts.

Filming will start on Iron Man 2 in the spring.