The third Iron Man movie is a lackluster effort that hammers maybe three good ideas into the ground for more than two hours. If you're a fan, you'll ... I can't say you'll be "satisfied," or "you'll have a good time," but you probably won't come out angry--unless you paid extra for the worthless 3D. But why don't you expect more?
Whedon takes a large, established cast from three established franchises (four if you count the Hulk, with a new actor yet again as Bruce Banner) and gives each character enough screen time, action and dialogue to satisfy the respective actors' devoted fans. Robert Downey Jr.'s Iron Man gets the star treatment, suited to his character's charisma and ego, and Chris Evans' Captain America comes in a close second. Chris Hemsworth's Thor could've stood a bit more development, but the rest of the heroes, comparatively second-stringers, get good play. Scarlett Johanssen's Black Widow is much, much better handled here than in her debut in Iron Man 2.
Robert Downey Jr. and Jude Law are great fun, elevating a textbook example of Hollywood cheapening its source material. You may be used to a Sherlock Holmes who is sober and competent, and who solves actual crimes using his wits and amazing powers of observation. This is not that Holmes.
Tropic Thunder is good. It's worth seeing and, given the action spectacle on top of the comedy, it's worth seeing on the big screen. The film is very funny, but cowriter/director/star Ben Stiller forgets sometimes that not everyone in the world is so wired into the important goings-on in Hollywood that all his parodic swipes at the freaky fishbowl he lives in are going to work.
Despite high hopes for the Batman sequel, the Indiana Jones comeback and the new Hellboy, it would not be a bad summer at all if the early arriving Iron Man turns out to be the best action-adventure of the summer. Jon Favreau, who does not have this kind of action movie under his directorial belt, just knocks it out of the park here, taking a very good script and an excellent cast and making it all explode off the goddamn screen.