Since this whole dust storm about TOR nodes and open proxies refuses to pass, maybe there's a business opportunity here for some tech-minded individual.
Seems like all it would take to solve this dilemma is an encrypted proxy that delivers the decryption code(s) to the WMF developers. So the editor gets privacy from User:JoeSchmoe but Wikipedians with a certain level of permissions could determine the point of origin.
Something like that would come in very handy for the editors from mainland China, and a couple of smaller countries that firewall access.
Sell advertising to cover costs or run it as a public service. If this were effective at scaling the Great Firewall I think some people would donate toward the endeavor. That'd mean seeking 501(c)3 tax status if it's based in the States (which is not so hard to get: open a dedicated bank account and file some forms).
AB, if you're really serious then how about taking this ball and running with it?
-Durova