Not to preclude any other ideas (and perhaps to complement them somehow), there will be an in-person celebration on Shabbat Parashat Vayeishev (Dec. 12-13) in Silver Spring, MD. By default, it will be one Shabbat meal for Yodeyans who happen to live in the area (and their families). If people are interested in coming in from out of town, we can put together a fuller-fledged Shabbat program.
Either way, I am proposing as a theme Mikra / Scripture, given that Mi Yodeya's turning five and the curriculum in Avot 5:21.
If you are interested in attending, please send me an email at the email address indicated in my profile (or any other email address you happen to have for me).