By Odin, this Thor: The Dark World concept art is amazing. Created by artist extraordinaire Nathan Schroeder, it shows some of the Nine Realms looking even spiffier than they did on screen. Plus there are some amazing animatics from the first movie.
Schroeder's epic concept art is exclusively on display over at Film Sketchr, so check out more of it there. Here are a few of our favorites:
Also, Film Sketchr dug up some great storyboard animatics from 2011's Thor, showcasing the Jotunheim sequence:
The creator of those storyboards, Tom Nelson, also posted some concept art from the first movie, including this look at Thor's brother Balder who could have been in the film: