Since the official thread is still closed (this could be merged in there, I guess), here's what I thought:
Spoiler!!! Click to Read!:
Bloody awesome. Really. It was surprisingly faithful to the material, with the necessary changes here and there, of course. They didn't go into Rhodey's history much and changed some stuff with Obadiah, but they certainly got the essences of the characters. It was a really fulfilling film. Definitely the best comic-to-film movie I've seen and enjoyed.
It has some really great scenes. Downey does great as the sarcastic Tony Stark, although he's less convincing when it comes to the serious stuff. One particular conversation with Pepper (Paltrow) felt a little hollow. Paltrow also did a splendid job. Sadly Happy Hogan didn't get a real role (played by Favreau). What little we got to see of Rhodey was great too. His interaction with Tony is great.
Stane too, wonderfully cast, although he ends up a bit two-dimensional in the end. There's not a lot to make you care for him, which isn't necessarily a bad thing, and the way he goes out is relatively lame. Flinging his arms up in a cheesy supervillain pose while struck with a blast from a reactor core. That leads to another point of contention, by the way: The armour was done beautifully and all the scenes with it are great, but the fight with Stane isn't as action-packed as I'd hoped. Still tense, but less slugfest and more Tony running for his life.
All in all, it was a great movie and one I'm sure you won't regret seeing.