Apparently they recently did a revamp, a lot of their static pages are 404s.
They have substantial numbers of images from Wikipedia and Wikimedia Commons (just do a search for either term and see).
They seem to extract the license OK (although could be good to check some edge cases, like country-specific CC licenses), and for 'photographer' it appears they take the last uploader. compare http://commons.wikimedia.org/wiki/Image:1cadarache-arrow.JPG to http://everystockphoto.com/photo.php?imageId=1656186. Strangely, they completely ignore the description.
They have a very simple interface to let people provide comments, tags and ratings. (I would dearly love to see simplified "tagging"/category functionality, and search-integrated rating functionality, enabled on Commons.)
I am very impressed by three links they provide on every page for people to report bad images:
* Copyright Infringement * Inappropriate Content * Poor Quality
cheers, Brianna