Gregory Maxwell:
As things currently are, the Wikimedia Foundation has the same obligations under the GFDL as I would have if I were to make a fork. So if I grabbed the databases, setup media wiki, and fixed the graphics so that I wasn't walking on any trademarks my position would be just as legal as the Wikimedia Foundations position. That's pretty fair and friendly: if I do the same things I'm all good.
With CC-wiki this wouldn't be the case at all. My fork would be a second class citizen. Even if all the editors moved to edit on Gregpedia, people would still need to credit www.wikipedia.org for the material.
Material written on Wikipedia would be credited to the Wikipedia community. Material written on Gregpedia would be credited to the Gregpedia community. This seems perfectly fair and reasonable to me and does nothing to preclude you from running and operating your fork, it simply notes the historical fact that your content was originally created by a different community, rather than misrepresenting it as originating with you.
You are correct that under the terms of the GFDL, I do not have to mention Wikipedia with a single word. I can, in fact, import the author histories into my Foopedia and create a new site that seems to have written 610,000 articles out of nowhere. I can even pretend that all these users have accounts on my site and import their user pages (if they have added "originally from .." templates, I can remove those). Many users will go to Foopedia and get the impression that I, as founder and operator, have made this thing happen, and that thousands of people have worked for/with me. They might even get the impression that all these people are right-wingers because I have Republican party advertising all over Foopedia.
Now, I would argue that this would be a gross misrepresentation of the historical facts, and that, if you want any licensing at all, a fair and reasonable license should acknowledge the community origins of the content, rather than allowing implicit or explicit false attribution to an entirely different community.
The content of Wikipedia is not the property of the Wikimedia Foundation.
Wikipedia, however, is not just a bunch of random people doing things that they would be doing anyway if Wikipedia didn't exist. It is people collaborating in a specific framework, working together as members of a specific community under specific rules. CC-WIKI is not about granting special rights to an organization, it is about acknowledging the community identity over the identity of individual writers.
As long as the emphasis is on community, rather than on organization, I think CC-WIKI is exactly the right approach.
I agree that GFDL conformant attribution is an issue in some media (although I disagree that it is an issue for electronic sources, if you can mirror the ~2ish GB of text in cur, then you could also manage the contributor names).
Many mirrors and forks are set up by people who are either not knowledgeable about licensing, or who do not have the resources to comply with the technical requirements (we do not make this easy for them). It's fine if you argue that you feel individual authors deserve attribution over the community as a whole -- that is a legitimate position to hold, although I disagree with it. But if you claim that you want to make forking and mirroring easier, then you are misrepresenting your position, because it does the exact opposite. CC-WIKI makes forking simpler and acknowledges the work of the community as a whole rather than that of individual contributors.
Erik