Talking to the Sunday Herald Sun (via Moviehole) for his upcoming "Australian tour"–apparently, Joss Whedon’s rock star status has him touring now–Whedon confirmed that Scarlett Johansson’s Black Widow would not be the only female role in the movie:
"It is true that the movie is only going to have one female Avenger, but she will not be the only female character," he told them, which makes us think some of the women from the other Marvel movies–maybe Gwyneth Paltrow’s Pepper Potts from the "Iron Man" movies?–would be making appearances in the movie.
Whedon is working hard on rewriting the script but he remained mum on what the plot would be, though he did say that it would incorporate a number of different Avengers stories, both from the original comics and the "Ultimates" version of the characters:
"It will be a new story that has many things from different arcs of the comics in it. There is no one Avengers story that you can just do the way that you can do the origin of Spider-Man. You really have to cull from the original and The Ultimates, which is one of The Avengers titles."
So we don’t really know that much more except that The Avengers will continue the path paved by the previous Marvel Studios movies rather than being entirely faithful to any one version of the comic books.
The Avengers is scheduled to open May 4, 2012.