Robert Downey Jr absolutely owned the role of Tony Stark. Owned it.
The first scene shown had a straight on shot of RDJ as Stark, presumably out in the field, talking to high level military types. He's making a speech about weapons of war and says something to the effect of:
"Some people say the best weapon is one you never have to use. I disagree. I think the best weapon is the one you only have to use once."
It then cuts to a number of very short scenes giving an impression of Stark as a character as a tough businessman, playboy (looks like a wide shot of him with a couple of hotties on some Vegas-style bed), and a charmer. In one scene an attractive blonde reporter tries to ambush him in an interview asking if he thinks of himself as a modern Da Vinci, to which he quips "Of course not, I can't paint." She then quickly asks him "then how about a merchant of war?" or some such thing, to which he replies "that's more like it."
We then see Stark in the desert at the moment of the explosion that embeds shrapnel near his heart, and then as he awakens, tearing the bandages from his chest to reveal the crude electromagnet (powered by a car battery!) that is keeping him alive. We see Yinsen briefly, and Stark building the armor.
And what about the armor?
Iron Man fans are going to soil themselves when they see this footage.
When we finally see the Mark I in action it's breathtaking - like a super-mobile tank on two legs. If you're thinking Robocop as far as the armor, forget it. It's more like Transformers, except withOUT the mind-jarring level of complexity that didn't even allow you to make out details.
The footage showed Iron Man smashing through a pair of steel doors, walking down a cave passageway like a dreadnought, tossing aside soldiers like they were made of straw. While smashing at something, one of the arms gets caught in the rock wall and a soldier takes a point blank shot at the helmet which ricochets off (to great comic effect, but in a good way).
He then comes literally blazing out of the cave entrance shooting flame throwers that seem to reach 40 feet.
And guess what? I'm pretty sure I glimpsed the Mark II that fans have been asking about, but only for a moment.
At first we thought we'd only get a quick shot of the Mark III armor in the form of beauty shot that zoomed the camera up to him just standing there, but then we were treated to scenes of Iron Man in full flight, zooming along with some military jets. It's a head-on shot of him and the jets when he suddenly breaks to the right of the screen far faster than they could. Then there are a number of panning shots of the armor in flight, all very fluid and far enough away to give a sense of scale but close enough that you can still make out some details on the armor. REALLY nicely done, and the uber-geek moment came when he dropped his arms to his sides, fired his repulsors in addition to the bootjets and rocketed away even faster, breaking the sound barrier in the process.
I felt like I needed a freaking cigarette when it was done. :-)
When Jon Favreau came out, there was applause and cheers, but let me tell you it was NOTHING compared to the noise that greeted him at the end of that clip and as he left the stage.
Iron Man opens in May 2008