Take a look to the official logo of Thor 2 aka Thor The Dark World

Thor 2 Movie Trailer

(Click on the picture to enlarge.)

The plot is still kept under wraps, but a stuntman inadvertently revealed that dark elves will be involved. So now people are speculating that the aforementioned elves are actually the Dark Elves of Svartalfheim, a bunch of evil villains from the comic book.

The release date of Thor 2 is set for November 8, 2013.
:)