We knew that Black Widow would feature in The Avengers and although Whedon has said there will only be one female Avenger in the film, he has confirmed that other female characters will appear. Moviehole have speculated as to whether that might mean an appearance for Gwyneth Paltrow’s Pepper Potts, or a possible third incarnation of Betty Ross (now that Bruce Banner has been recast, it would seem logical to recast Betty as well), but for the moment we will just have to wait and see.
Whedon said of the story that it will be new, but coming from various arcs throughout the comic series, including the original and The Ultimates. It seems there is no shortage of material to draw from which will hopefully result in something that feels fresh rather than the potential bloating that could result from trying to draw so many characters together (as, for example, in Spiderman 3).
The Avengers is due to hit our screens in the summer of 2012, with Robert Downey Jr (Tony Stark/Iron Man), Samuel L. Jackson (Nick Fury), Scarlett Johansson (Black Widow), Clark Gregg, Chris Hemsworth (Thor), Chris Evans (Captain America), Jeremy Renner (Hawkeye) and Mark Ruffalo (Bruce Banner/Hulk) all on board so far.
Thanks to Moviehole for the heads up on this.