I'm not going to respond to all the points raised in your e-mail, Sue (partially because most of them are just too general), so let me just mentioned some of them.
The editors are responsible for the projects: the Wikimedia Foundation knows that, acknowledges it, and is deeply appreciative (as are all readers) for the work that volunteers do in the projects. The Wikimedia Foundation is responsible for the Wikimedia Foundation wiki (and the blog).
Then it should perhaps be renamed as the Wikimedia Foundation Blog With Guests Post from Community Members.
We are grateful to get community help there, and a small number of community members do really good work with us on both the WMF wiki and the blog. But ultimately that wiki, and the blog, are our responsibility, and we are accountable for making sure that e.g. the staff page, the Board bios, the resolution texts, etc., are maintained and in good shape. Most material on the WMF is not created via collaborative production processes -- it's "corporate" in nature, meaning that it is developed by the Wikimedia Foundation, for an audience of Wikimedia Foundation stakeholders, which includes community members and prospective community members, donors, readers of the projects, media, and others.
Well, then I am still surprised to see you thank those volunteers for their work in this matter—by desysopping them all in one, unannounced and not discussed user rights purge.
The most important reason why all those pages that you mention, Sue, are maintained and in good shape is that community members have been very often driving changes, helping with importing translations, and making thousands of small changes (be it typos, categorisation or design-like).
Seeing that there aren't any WMF employees who contributed as much time and work as some community members (with the possible exception of Philippe and Heather), I'm puzzled to see you make this decision.
This having been written, I would like to reiterate my questions again (and add another one):
1) Who made the decision to remove adminship from all community members? 2) Why did you make this decision now? What changed? 3) Why did you decide to desysop people straight away instead of discussing things with them first? 4) /NEW/ Who precisely (what department) is responsible for the maintenance of the wiki, and why didn't they perform their roles before?
-- Tomasz