As we already know, Marvel's upcoming superhero sequel "Thor: The Dark World" will score both a mid-credits scene and a post-credits scene.
Talking with Bleeding Cool, the film's director Alan Taylor says he did not direct the mid-credits one.
The scene in question includes a blond Benicio Del Toro as 'The Collector' from James Gunn's upcoming "Guardians of the Galaxy". When asked if he directed it, Taylor replied:
"I absolutely did not. I am very happy to not take responsibility. It's a different tone. I would have shot it differently.
But I think it's cool that it reaches out and touches that other universe. That universe is coming. The 'Guardians' universe is really cool and wacky, but that sequence in the credits, I would say, is the only part of the movie where I'm happy to give the credit away."
Taylor in fact wasn't sure if it was Gunn who directed it:
"I wouldn't blame it on James Gunn. It's clearly his sets and his characters, [but] I wouldn't attribute it to James Gunn."
Marvel's Kevin Feige later confirmed that it was Gunn who directed the scene. As for what happens? Comic Book has a description:
After the Aether is back in the hands of the Asgardians, Sif and Volstagg bring the item to the intergalactic museum of none other than The Collector, played by Benicio del Toro . The reason for this is that the Tesseract is already on Asgard and they should have no two Infinity Stones in their possession. When he is alone with the Aether, The Collector utters the phrase, 'One down, five to go'."
The second scene at the end of the credits is more of a comic relief scene and sets up a third "Thor" movie:
"Thor returns to Earth and into the arms of Jane Foster, and they share a passionate kiss. The God of Thunder clearly chooses to be with her. In the last scene, a beast from Jotunheim pops up in London, having previously passed through an interdimensional passage during the Convergence during the final battle."