Today I added a feature to git annex unused that lets the user tune which
refs they are interested in using. Annexed objects that are used by other
refs then are considered unused.
Did a fairly complicated refspec format for this, with globs and include/exclude of refs. Example:
+refs/heads/*:+HEAD^:+refs/tags/*:-refs/tags/old-tag
I think that, since Google dropped openid support, there seems to have been
less activity on this website. Although possibly also a higher signal to
noise ratio. 
I have been working on some ikiwiki changes to make it
easier for users who don't have an openid to contiribute. So git-annex's
website should soon let you log in and make posts with just an email address.
People sometimes ask for a git-annex mailing list. I wouldn't mind having one, and would certianly subscribe, but don't see any reason that I should be involved in running it.
after years subscribing to zillions of them, i have acquired an allergy to mailing lists. it seems that i get this every once in a while: i'm subscribed to a bunch of them and i stop reading and just hit "d" on my mail client.
i think there are very interesting alternatives, online web forums (yes yes, i know, bear with me) where knowledge is established and shared instead of just having a threaded conversation. i'm thinking of http://ask.debian.net/ or the stackexchange sites. as i analysed before, the forum is the biggest part of this website (and consequently the git-annex source code!), bug tracker coming in second, and the two together forming the majority of disk usage of the git repository. there are alternative discussion tools like discourse.org that may also be interesting for people wanting to run such a service.
anyways, the ideas of those is to converge on a set of FAQs and knowledge items more than just have random discussion, and force people to reuse existing topics.
if i had more time, i'd probably setup something like this but really, i can only encourage those initiatives at this point.
interesting! i didn't think of those requirements, which do seem quite stringent, but i am certainly sensitive to them, considering i will be spending my own significant amount of time with intermittent access soon.
i have opened a todo item to move the discussion somewhere more relevant, see enable a discussion forum or support system.