Yah, I might not have much to submit now lol Games tiles seemed like a pretty tapped commodity right now. I know I can still find a few and then find some cover arts for regional releases, but that will take a bit more doing then altering urls.
I just went down the list of games unreleased and checked them 1 by 1. Probably an easier way though. Still a bunch of games that need them that have been added to to the site, but don't have a page on xbox.com so an image doesn't exist yet.