Other notables were Sam Rockwell as a bumbling business rival to Tony Stark, Don Cheadle taking over from Terrence Howard in the role of Stark's best friend/future War Machine James Rhodes, Garry Shandling as a conniving & skeevy senator, Samuel L. Jackson as Nick Fury and director Jon Favreau as Stark's driver.
Great effects and action sequences! Some will complain that the middle was a bit slow, but it didn't bother me too much. It kicked ass! Go see it!
p.s. Stay til after the credits, nerds. You'll thank me after.