See Talk:licenses for a hopefully-compatible disclaimer. There are issues that Wikipedia is running into that we can avoid:
1. GFDL requires listing the five most important authors - Wikipedia doesn't do this, so it violates the GFDL.
2. GFDL requires open access to source text format with no limitations - Wikipedia uses hard-bans that prevent some people from retrieving source text (there's an option or prior version that lets banned users retrieve source but not re-submit it, which policy does not violate the GFDL except in spirit).
3. Change of license would be near impossible on Wikipedia given the huge number of contributors who agreed to submit to the judgement of no one, not even Jim Wales (he is not mentioned in the GNU GFDL, nor on the Wikipedia disclaimer). It will probably be the subject of power struggle in future, or forks that want to add invariant sections, credit authors or editors or certifiers that the material is accurate etc. This can be avoided by offering "a vote" or "a voice" to authors or editors in the Consumerium Governance Organisation, however that works, and mentioning that in the disclaimer.
4. Wikipedia allows anonymous and pseudonymous contributors, but some users and even some sysops try to identify which ones are "the same people as" which other ones, and even amazingly try to pin "real names" on some combinations of these accounts. This "outing", for whatever reason, makes it possible for anyone who is named this way to claim "well yes I wrote that but no I didn't submit it to Wikipedia, either they stole it or someone else submitted it there without my permission". Wikipedia couldn't fight claims like this if they had allowed any "outing" by anyone with any official status, e.g. Jim Wales, or a sysop perhaps. If there are open secrets that a lot of people believe, it becomes really hard to justify not getting in touch with the people supposedly responsible and asking them if they approve of the material being re/published or not. It would also be important to make clear what is the obligation to credit authorship of anonymous authors, and get them to give up this right when they hit "save". At present the Wikipedia disclaimer doesn't do this, and there is an obligation to (ridiculously) find out who wrote anonymous stuff so you can credit them for it.
5. m:Wikipedia Governance is so bad that it is a laughingstock on other wikis. They are a bad model to follow. We should be leaders in this regard, have a WikiCourt, etc., so no one can claim they were unfairly treated, and never mind the ability to cause legal trouble, they won't want to, if they have been treated with a proper process.
6. Consumerium Governance Organisation must have power to just join some consortium of producers in future, if the license trouble emerges, or if the whole project ends up fusing with another like the Adbusters barcode scans or some audit procedure for Slow Food ark of taste products, or any safe trade thing to identify GMO products, or fair trade stuff. These are all so similar to Consumerium to it would be smart to reserve the right to merge into them all, and make them all work using whatever license Adbusters, Slow Food, Greenpeace, Ten Thousand Villages, etc., like, rather than trying to tell them how to do what they have been doing for decades and being propaganda for GNU. Remember many of these groups are suspicious of new or free technology!