Official plot synopsis for Thor: The Dark World - 

In the aftermath of Marvel’s Thor and Marvel’s The Avengers, Thor fights to restore order across the cosmos… but an ancient race led by the vengeful Malekith returns to plunge the universe back into darkness. Faced with an enemy that even Odin and Asgard cannot withstand, Thor must embark on his most perilous and personal journey yet, one that will reunite him with Jane Foster and force him to sacrifice everything to save us all’

Thor: The Dark World is being directed by Alan Taylor (Kenneth Branagh opted out of directing the second film), and will star Chris Hemsworth, Natalie Portman, Tom Hiddleston, Stellan Skarsgard, Idris Elba, Kat Dennings, Jaimie Alexander, Rene Russo and Anthony Hopkins.

Filming began in September allowing for a release date of November 8, 2013. 

The second Avengers film, being directed by Joss Whedon, has been given an official release date of May 1st, 2015. 

No official title for the film has been announced as of yet. 

Joss Whedon has confirmed that he will be helping to develop a live-action Marvel universe TV show for ABC, as well as returning as the director for the second Avengers film.  

There are very few details regarding the show, however, is is expected to center around SHEILD and will most likely involve lesser known Marvel characters. 

The second Avengers film has a tentative release date of 2015, with filming anticipated to begin early 2014.  

Christopher Eccleston (G.I. Joe and Doctor Who) has been confirmed to be playing the role of Malekith The Accursed of Svartalfheim in the upcoming film Thor:The Dark World.  

Malekith is a long standing villian of Thor’s and is one of two primary elves within the mythology of the Marvel universe (the other being Kurse). Mads Mikkelsen, who was originally cast as the leading villain, was forced to drop the role due to scheduling complications.  

The film is being directed by Alan Taylor (Game of Thrones) and will star Chris Hemsworth, Natalie Portman, Tom Hiddleston, Jaimie Alexander, Zachery Levi and Ray Stevenson. 

Marvel has announced that Thor:The Dark World will hit theaters November 8, 2013.