Whilst discussing membership, there is one group who may have a problem worth considering.
Wikipedia encourages editor privacy. This is built into every policy, so much so that Checkuser is not accessible without at least two checkusers to monitor each others' actions. Personal information is very well protected, for many good reasons, and on the whole this works well and is core policy on all Wikimedia-operated sites.
Some of our best editors prefer to work anonymously. In my case for example, I edit on controversial articles, and I'm listed as an admin (and editor of several years standing) willing to make difficult blocks where vicious personal attack may arise on and offline. I've been involved in blocks of vandals who have pursued other editors offline into their daily activities and professional lives in revenge, and I have had a stalker on Wikipedia who has made libellous claims..... all of which is water of a ducks back that I don't have a concern over, and doesn't influence editing and mediating as seems most appropriate within Wikipedia ... because no public link to an offline ID is provided.
I'd like to support Wikimedia UK in this manner too, and become a member to express support for the endeavour, and actively work within it. Especially since Wikimedia UK will be a significant aspect of Wikimedia in the UK in future. There needs to be found some way to allow this whilst not publicizing personal details (whether legally on company filings, or in minutes under "real names"). Otherwise interested parties who are not inclined towards self- disclosure (which is their right) will be fully prevented from such involvement in perpetuity. This would affect a large number of editors, admins and experienced people.
I'm not sure how this can easiest be got round, legally, but I think it's an important one. I can think of a few ideas.
For example, is there a facility for some form of "anonymous members trust", that is named as a paid up member of Wikimedia UK with as many votes as the number of donating members it represents? The trust is named and has Wikimedia UK as trustee, but it would then be under no legal obligation to disclose the names of those it represents (since these editors would be mere donors to a trust who donate anonymously or under pseudonyms, hence not required to be named). Might need memo and art's modifying slightly to allow for the trust to speak and have a "block vote" in this way. (A representative or spokesperson of a trust again being under no legal obligation to ID themselves, unlike a trustee ... and all paid up donors could be declared "representatives" or "spokespersons" with the right to speak, and one vote apiece in the trust's vote on any issue.)
That's one route that works, legally. There are bound to be others. Either way I think it's important to consider them, to avoid disenfranchising every one of our best editors who have the right to anonymity for their own reasons on Wikimedia sites and activities, and might not wish to waive it in order to contribute further.