First up some possible concept art... for Captain America: Winter Soldier...
The next peeks are from the just released Marvel Cinematic Universe Phase One Blu-Ray set.
Again some concept art for Captain America 2 of the Winter Soldier, Falcon, and Cap in action.
Images via ComicBookMovie.com.
Which also has these very cool Thor: The Dark World behind the scenes
GIFs gleaned from the Blu-ray set. See more here.
Update more cool stuff from the Blu-ray set. More Thor GOG and Ant-Man! Also via CBM.com