Pretty Frickin' Good. Scroll down for more.
This movie could have been a mess with the multiple plots and a whole ton of characters. Thankfully, the movie makes the correct choice of clearly putting Tony Stark (played perfectly by Downey Jr, but you didn't need me to tell you that did you?) at the center of this universe. This is a much more character driven vehicle than the last outing, and well, if the movie can at times seem a little ponderous and even scattershot, it makes up for by moments of being purely frentic and hyperactive - much like Stark himself.
As for the other actors in the film, I feel Sam Rockwell deserves special attention for his turn as Justin Hammer. Rockwell could have easily been submerged given the level of the actors he was put beside (particularly in his scenes with Mickey Rourke), but he manages to hold his own as well, the less than charismatic, "poor man's Tony Stark". In particular, an early scene in Monaco does a lot to make the character almost sympathetic - it has to be hard suffering in the shadow of Tony's unique combination of genius and asshole. Similarly in Tony's shadow is Lt. Col. James Rhodes (played by Don Cheadle, who brings the necessary gravitas to contain Downey's mania in key scenes), who is given a rather nice and understated conflict between his sense of duty to his friend and to his country. And really, nothing needs be said about Mickey Rourke - you either like him or you don't. Sadly most of the rest of the cast are underplayed in the film, and a few extra minutes to help develop them wouldn't have hurt.