The major differences are to the left of the Tauntaun's leg. I did a little cloning to make that area darker so the logo popped more. It looks fine on the DVD cover, but looks odd without the logo.
This is by far my favorite poster for any Star Wars movie, followed closely by the Revenge of the Jedi teaser.
I found my original and I only shaved a few pixels from the top. The rest of the image is identical.