Thor: The Dark World opens a week earlier in the UK than it does in the United States, so some early press screenings have already taken place in England. Multiple sources, who have attended these screenings, are reporting that Thor: The Dark World has not one, but two different post-credits scenes.
One of the scenes occurs during the credits, and the other scene occurs after the credits are over. Everyone who has attended a screening is under an embargo, so there are no details yet on exactly what happens in the two scenes during the credits. It's likely one of them is a comic relief scene related to the movie, and the other is probably a tease for an upcoming Marvel Studios movie. However, that is just speculation, as we have not seen an early screening (and if we had we would likely be under embargo as well and unable to write about it).
Because of the embargo, there is very little feedback that has surfaced on the quality of the movie yet. One message board poster did give it a 8.5 out of 10 and ranked it as being 2nd or 3rd out of all Marvel Studios films.
Word is that the British embargo lifts on October 24, 2013, so expect full details and spoilers on the film to land online well before the U.S. release.