I believe we should also have a way of making dead-tree sources available (through scans etc) for verification. Currently, we don't seem to have any way of uploading a scan of a page or whatever, simply for the purpose of verification. It wouldn't be for inclusion in the article itself, and possibly restricted to logged in users, but I would have thought this would easily satisfy "fair use".
Fair use generally only applies if you are using the copyrighted material in an article about the material itself. Using it as a source isn't "fair". Most dead-tree sources can be found a good library, which should be enough to verify it if we need to.