I've been looking for this for weeks. And most of the youtube entries are taken down immediately. But on this site, I'm lucky to snag a copy.

The footage features most of the movie's main cast including Robert Downey jr. as Stark, Samuel L. Jackson as SHIELD director Nick Fury and Gwyneth Paltrow as Pepper Potts. Also included are footage with new characters such as Mickey Rourke as Whiplash, Scarlett Johansson as Black Widow and the new actor to play James Rodes, Don Cheadle.