Hall H at the 2010 Comic Con in San Diego was officially OWNED by Marvel Studios last night with the world premieres of exclusive footage from the forthcoming Thor & Captain America: The First Avenger.movies.. But…
The official shutdown of the entire Comic Con was seems to be the Avengers movie panel.

A short teaser trailer was played which showed Nick Fury played by Samuel L Jackson talking about the Avengers Assembling andd as the trailer faded Samuel L Jackson appeared and proceeded to announce and introduce the rest of the Avengers cast to the stage.
Jackson was joined by: Agent Colston (played by Clark Gregg), Black Widow (played by Scarlet Johanssen), Thor (Played by Chris Hemsworth), Captain America (played by Chris Evans) and the blockbusting Tony Stark aka Iron Man (played by Robert Downey Jr.) all on the one stage!

Then Robert Downey took to the mic to state that the Avengers movie would be a more ambitious movie that the recent Leonardo Dicaprio smash hit Inception, before introducing to the stage, Hawkeye (Played by Jeremy Renner) and then…
Bruce Banner aka The Hulk who after several rumours will be played by Mark Ruffalo. Ruffalo will be replacing Edward Norton as the Hulk after Marvel Studios fell out with the actor reportedly due to contractual disputes.

The Avengers movie will be out in 2012…. I bloody can’t wait!!

[Source]