If you stick around after the ending credits of Iron Man 2, you'll get a surprise that expands the Marvel movie universe, just like with the first movie. We glimpsed this scene, and here's what happens. Maximum spoilers below!
Somehow, the "after credits" sequence from Iron Man 2 wound up on YouTube for a short while, and we had a chance to watch it before it was, not surprisingly, taken down.
Here's what happens:
We see a desert landscape, with sandy dunes punctuated by the occasional bit of scrub. There are mountains off in the distance. A black car zooms across the screen, dust and exhaust in its wake. The car swerves and roars towards the camera, and we see its New Mexico license plate: 8RE 2Z1. A man steps out of the car, and then we see him standing on top of a tall hill with a single tree, looking down at something.
The man is revealed to be SHIELD agent Coulson, wearing dark glasses and a dark suit.
He's looking down at a smoking crater, which is being circled by a bunch of cars, as feverish activity takes place around it. He turns away from the crater, and touches his earpiece. "Sir," he says, "We've found it." The camera pans back to show what's in the crater — Thor's hammer, looking much like it does in the comics.
Smash to black.