Daniel-
What we need is the ability to mark "used with permission" and "used under non-commercial fair use doctrine" images.
I'm not sure we can really allow anything besides public domain, fair use, FDL and FDL-compatible licenses. If I understood the FSF statement on our fair use questions correctly, the FDL simply does not apply to fair use material. This cannot be said about material that is specifically licensed as non-commercial or under special permission.
We can still argue that the images and the text are separate, but that argument is far more difficult to sustain and probably more problematic in terms of our open content goal.
I do think we need to develop better guidelines on image use to encourage the use of boilerplate requests and to discourage the use of "fair use" images when we clearly could take a photo of our own. We do also definitely need copyright flags.
Perhaps we could streamline the process of getting permissions, at least by having a Wikipedia: page where people can dump image URLs and other people can send the requests, to share the workload.
I think the trick in getting FDL permissions is to write better letters. We need to use positive, uplifting words like "copyleft" and "open content", and we need to create some enthusiasm for Wikipedia, and all that without the letter sounding too spam-like. We should probably focus some energy on creating better boilerplate letters. For private individuals, "public domain" may work better than "FDL".
Regards,
Erik