Before a movie opens, we're all eager to see the concept art so we'll have some idea of what the film will look like.  After the film opens, concept art is still great because it shows us the roads not taken.  Artist Andy Park has posted plenty of concept art from The Avengers on his website, and it's worth checking out.  Some of the changes are drastic (I can't imagine Nick Fury without his black trench coat), and some are nice and subtle.

Hit the jump to check out the concept art.

Click over to Park's website to see more images [via SHH].