Thor: The Dark World is the name for next year’s sequel to the first Thor movie.

What is the Dark World?

There are a few possibilities:

Enchantress and Executioner

The Enchantress (Amora)  is a great Asgard Macguffin.  She can control minds, cast powers, travel through time, space and dimensions, bestow powers on others or anything else she pleases really.  She is in love with Thor and will alternately manipulate or be manipulated to further that end.

The Executioner, also known as Skurge, has enhanced strengths and abilities even above the average Asgardian.  He also carries a nasty axe.

Dark Elves

Malekith the Accursed is the ruler of the Dark Elves.  He possesses super strength and power.  He can cast Dark Faerie magic.  At times he has been in control of the Casket of Ancient Winters — a device which reproduces the cold of the Frost Giants’ world.

Hela

Hela is the Asgardian God of Death and thus her powers are damn near limitless.  She is also the daughter of Loki.

 

Any one of these characters could bring about a “Dark World”.

UPDATE:

James Grogan, a stuntman on the upcoming movie said the following in an interview with I Review Too:

“The other day for example, this is quite random but I was working on Thor 2,” he explains, “I had a load of stunt guys in and the director came in and he said ‘Look, we want you all to be elves,’ and I was like ‘What the hell is an elf anyway?’

Full article linked to below:

http://ireviewtoo.wordpress.com/2012/06/12/news-chris-hemsworth-will-encounter-elves-in-thor-2/