Specifically: Wikimedia is recognizing 'new models of affiliation',  which means that various kinds of groups, including those organized around a common interest that isn't geographically bounded (librarians!) or those which span some kind of non-legal geography (Cascadia). I can also +1 what SJ just said.

I would love to see the WM-US group explore really innovative ideas about what such a geographically broad organization might do and what themes it might encompass; how it might help local meetup groups and local Wikimedians, and what activities a group might take on. Like Pete, I personally tend to gravitate more towards planning events and outreach than planning new organizations. I doubt we're alone in this; however, despite that it's been historically difficult to keep meetup groups going in the proposed Cascadia geography, despite high numbers of wiki-interested people in many areas (Seattle, Portland, BC, SF all have strong collaborative tech communities). So I wonder how a new organization might work with or help that.

Lastly, since this is the San Francisco area list and we haven't seen a whole lot of local activities recently: I want to remind everyone that organizing a meetup or other activity is as simple as posting a notice here:
http://en.wikipedia.org/wiki/Wikipedia:Meetup/San_Francisco

and then letting us all know about it on the list!
Feel free to use the talk page or the list to discuss logistics and ideas, too. I would personally love to see more activities, or just social get-togethers, and more stuff in our greater region (the South Bay, Sacramento!) would be cool too.

There are a lot of possibilities that *don't* require a formal organization to pull off, and a lot of people in this group (we have a couple hundred subscribers) who are game to do something!

cheers,
Phoebe