Joss Whedon recently caught up with EW (via Collider) and revealed that Captain America (Chris Evans) will the guiding point for audiences into the story. “I set out with a very simple problem: There is no reason for these people to be in the same movie. So that’s what my movie has to be about. So much of the movie takes place from Steve Rogers’ perspective, since he’s the guy who just woke up and sees this weird ass world. Everyone else has been living in it,” he explained.
The move makes sense both from a narrative standpoint and in the grand continuity of the Marvel universe. As you remember, "Captain America: The First Avenger" closed with Steve Rogers revived in present day Manhattan and completely out of sorts, so to follow that thread into "The Avengers" is a smart idea. And narratively, sticking with one hero and letting him experience and interact with a world that now includes Thor, Iron Man, The Hulk, Hawkeye, Nick Fury and Black Widow is an easier and more effective way to navigate all those personalities. Let's face it, Whedon is no Robert Altman and while a "Nashville"-styled superhero would be fascinating, the approach probably isn't right for a major tentpole.
Just another kernel of info from the film that will likely soon start a blitzkrieg of promo in the run up to its May 4th release date.