That's a nice idea, this particular form significantly shortened my mouse's life expectancy. ;-) Going through that list though, I find that while there are complete module packages that are unused at the moment, we haven't yet ruled out any of these, but maybe we should:

CCK-Signup (+CCK Sign-up notifications) / Signup:
One of them can presumably be dropped, unless there's some dependency I'm not aware of, but at least on the module dependeny level they seem unrelated. The idea was that Signup could be used to organize conferences. However, we recently discussed the maintenance of conference pages at the meeting in Leipzig and found that it would be nice to upload talks (with inline viewing using pdf.js), assign them to the conference programme and (most importantly ;-) ) allow users to manage their own slides/abstracts etc. It's still unclear whether signup will work well with these ideas.

drupalchat:
The drupalchat version history seems to stagnate now, so it would not be completely useless to reimplement (as was done with prior versions) our latex support via MathJax. Testing on my home machine revealed that multi-user chat seems to work now, even using AJAX instead of setting up an extra node.js server.

ThemeKey:
This was highly useful during theme development, but all that's left in that direction would be to maybe go through our CSS and find out if there are any redundant or inconsistent things, nothing that would justify switching themes entirely to avoid crashes with any template engine related functions...

Maybe we can discuss our module choices for the conference organization part as well as our other "under construction" sites at another good old coding sprint once Jan is back (Theme maintenance, drupalchat, module cleanup, username sorting and/or taxonomy synonyms maybe also before @Eric ?)

Jan told me that he's back 02 Jan 2013, but maybe we can even continue this year? :)

Works for me!