If there was any doubt that "serious actors" could be attracted to superhero films, consider it further banished with the rumor that Oscar Winner Tim Robbins may be playing Tony Stark's father, Howard Stark, in Iron Man 2. According to Latino Review, Robbins will be taking over the role of the elder Stark in an important flashback sequence.

According to the scooper, director Jon Favreau was unconvinced that Gerard Sanders (who played Howard Stark, father to Robert Downey Jr.'s Tony Stark, in the first Iron Man) had the acting chops to carry such an important scene.

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And why is it such an "important scene"? Well, it seems like that scene is going to help set up both The First Avenger: Captain America and The Avengers. The timeline works out right for the elder Stark to be involved with the Super-Soldier experiment, alluded to in Marvel's other recent superhero film, The Incredible Hulk.

And if that wasn't enough superhero casting rumors about Iron Man 2, the source also says that Hawkeye and the Black Widow are both also in the film - and not just in cameo appearances. Rumors about the Black Widow's appearance surfaced awhile back when casting calls were released that suggested both the appearance of the Widow and the appearance of classic Iron Man villain the Crimson Dynamo, but this is the first we've heard about Hawkeye possibly appearing in the film.