Well, toddled off to see the Iron Man movie last night, so what are my (spoiler-free) thoughts on it?
Put simply, it's one of the best comic movies ever. The film draws you in immediately, with Downey Jr winning you over within two minutes. His Stark is primarily based on the attention deficit-afflicted Ultimate Tony Stark, although his post-reformation scenes are morr like the more glarey and stern traditional MU Stark. Smooth and likable, Stark is a joy to watch (and I'd like to fly with HIS airline, please!).
The film is built on Stark/Downey Jr's character and is one of the more rewarding comic movies, siting somewhere between Spidey and Batman Begins in tone. There is action, but not a huge amount but it's never a problem as Stark is so entertaining to watch (especially when testing his armour) but the plot is fairly lightweight (being more of a spiritual rediscovery rather than a physical ordeal. The second half (after the well-played out origin) suffers as a result but is still fun. The armour is impressive, Jeff Bridges couldn't fail as Stane and Professor Yinsen is transformed into a fully rounded character---there's even a reference to Iron Man's arch enemy for those in the know.
One weak spot is Rhodey...though likable and well acted, Terence Howard just doesn't have the grit Rhodey needs. Jamie Foxx would have been better. Gwyneth Paltrow on the other hand is a revelation---although as wet and limp as boiled cabbage in real life, on screen she is radiant without ever being overtly pinup material. She makes Pepper Potts shine and one of the film's strong points.
Last thing...as the end of the film approached, I grew restless as a promised scene did not appear, even most of the way into the credits. If you are so inclined, stay until AFTER the credits to watch a certain one-eyed spymaster approach Stark from out of the shadows...