Natasha Romanoff (Scarlett Johansson) attracts the attention of Tony Stark (Robert Downey Jr.) in Iron Man 2. Both actors will be in the Avengers movie, reprising their superhero roles.Natasha Romanoff (Scarlett Johansson) attracts the attention of Tony Stark (Robert Downey Jr.) in Iron Man 2. Both actors will be in the Avengers movie, reprising their superhero roles. (Industrial Light and Magic/Marvel Entertainment/Paramount Pictures)

Fans got an unexpected treat at the annual Comic-Con festival in San Diego when the star-studded cast of The Avengers film took to the stage in a surprise unveiling.

Festivalgoers got the first public glimpse Saturday night of the film's cast after the day's movie panels wrapped up. Marvel Studios chief Kevin Feige stepped out onto the stage and began calling out the cast as 6,000 stunned fans at the pop culture extravaganza looked on.

The Avengers, due in 2012, weaves together the stories of Hulk, Iron Man, Thor, Captain America, Black Widow and others. It's a comic book fan's dream film.

The all-star cast and their comic alter egos are:

  • Robert Downey Jr. (Iron Man).
  • Chris Evans (Captain America).
  • Scarlett Johansson (Black Widow).
  • Jeremy Renner (Hawkeye).
  • Samuel Jackson (Nick Fury).
  • Chris Hemsworth (Thor).
  • Mark Ruffalo (Hulk).

Joss Whedon, the brains behind the TV series Buffy the Vampire Slayer, confirmed just a few days ago that he was directing Avengers.

"I will say the thing I love about it, the thing that made me excited to do it, is how counterintuitive it is," he said during a Comic-Con panel on Thursday.

"These people shouldn't be in the same room — and that is the very definition of family."