I am not quite sure why you might want a policyassigning all copyrights to the Wikimedia Foundation. First, this would be an administrative nightmare to change the licensing in midstream. Those who have contributed to any wiki type project are doing so with the understanding that their work can be edited, changed, etc. even if they don't grant any kind of additional license. However, they do not give up their copyright, with or without attribution. If they do not grant an open license then just posting it on a wiki type space is legally no different than writing someone a letter (though the issue of publication may come up). Regarding anonymous and pseudononymous works both are protected by copyright under US and foreign copyright laws, as the case may be. The author of the letter retains copyright.
Regarding people making contributions under any kind of specific license (be that open in the case of the WP community, or closed in the case of AOL) it is just a license, it is not the transfer or assignment of copyright, thus the original contributor under an open, non-exclusive license could still sell her or his work or have it published commercially, (without the GNU notice) though someone who discovers that it is posted with a open license could then also publish it commerically (as long as the GNU Free Documentation License notice is then included).
I should also remind you that everything done on a wiki space IS in writing, the question being who wrote it is a question of proof, but it is written and recorded.
I am not certain why there is a discussion of assigning copyright to the Wikimedia Foundation. Of course anyone is free to make such a contribution (though I doubt they will get a tax deduction for it) but it is not necessary IMHO for Wikimedia to use materials under the open license it already has, perhaps I do not understand the question, but what specifically cannot be acheived with the current open license that every Wikipedia contributor grants when they make contributions to any Wikipedia space? Is anyone really worried that contributors will start publishing their original contributions commercially (that includes publication by a not-for-profit corporation, many so called "small press" publishers are exempt under 501(c)(3) and their publications are sold in bookstores, i.e. most University Presses).
Alex756 (the lawyer mentioned below)
On Fri, 1 Aug 2003 07:10:47 -0700 (PDT) Karl Wick said:
Wasn't there a lawyer who offered free services to Jimmy a while back ? An expert opinion would he helpful in many issues to make a plan that is legal and helps achieve WP goals and mission, such as regarding the proposed dedication of copyrights to the Foundation.
--Karl