There's always that conundrum for American-made, American-marketed films that depict something taking place in a foreign country. On one hand, it's ridiculous for the people in the film to be speaking English if they're in a non-English-speaking country like ... say, Germany. On the other hand, it would be hard to market said movie if it were in German with English subtitles.
When you think of the upcoming Thor movie from Marvel, the first director that comes to mind is probably not someone best known for his Shakespeare adaptations, right? But that's exactly who might end up with the job, since Kenneth Branagh is in talks to direct the movie. Not that Shakespeare can't be a big-old action film (after all, Branagh's own Henry V was plenty action-packed and bloody) and big-old action films can't be Shakespearean. But it's not the first thing that comes to mind when you think of part of the Avengers, of which Iron Man is a part. And Iron Man is awesome and everything, but definitely not Shakespearean. He's too futuristic, and he's a superhero in a suit and all of that. Not exactly Shakespeare's specialty.