Saw this over the weekend. And I must say, I was impressed!
Non-spoilerrific:
I was struck by just how much S.H.I.E.L.D.'s engineers were influenced by the Kuat Yards school of bridge design.
Robert Downey, Jr. definitely was able to pull off the "smartest guy in the room" vibe for Starke. His dialogue was just plain fun, the whole way through the movie. And the interplay between him and Potts was absolutely believable.
I'm still not entirely sold on Mark Ruffalo as Banner. Still, the Hulk scenes where he's actually green are just awesome. And getting Lou Ferrigno to do the voice was pure genius.
I like the way that all of the heroes' backgrounds were worked into the story; just enough to get a feel for what each of them is like but not so much as to overwhelm the audience with detail. It's a great way of "showing, not telling" the characters' personalities.
The movie did a great job of showing each character's limits and abilities, with each of them finding a role and living up to it.
Now for the spoilerrific stuff...
Agent Coulson dying was...not unexpected. What a way to go, though. On the other hand, I still think that he might be alive. That still could have been an LMD that Loki "killed", or Fury could have lied about Coulson being dead to the bridge crew. My impression is that Fury is not above lying about that to bring the heroes together. And I could see Coulson going with it. Neither of them seem to have any qualms about going to extremes to protect the Earth.
Agent Hill did a great job of making me believe that she's a worth successor to Coulson, though. Apparently (according to the Wikipedia page on the movie) she didn't get a trainer through the studio. So, instead, she went out and hired one out of her own pocket to be able to bring her character's actions verisimilitude. Not something you see very often, and it definitely shows through on-screen. Honestly, I found her scarier than Black Widow in combat.
I love the scene where Cap is admonished by Black Widow that he should stay out of the fight between Iron Man and Thor. "These guys are basically gods." "There's only one God, ma'am." What a line to have just before jumping out of an airplane into a lightning storm. And the following fight definitely shows how Cap's strengths are useful to the team.
As everyone has mentioned, Loki definitely never read the Evil Overlord list. He definitely paid for that when he ran afoul of The Hulk. I laughed really hard at that one.
Also, the cop asking Cap why he should take orders from a guy in a spandex suit? Great scene. A little predictable, but in a good way.
My only real complaint is the method of getting people back from Loki's brainwashing. I mean, hitting them on the head? Isn't that...kinda cliche, nowadays? Still, I'll give it a pass considering how good the rest of the story is.