I have just signed up for csbigbang, a Chalet School bigbang due to go live in November. In my defense, it's only 10,000 words.
I am thinking sequel to Companions at the Chalet School, which will pull it firmly into the world of the other two bigbangs I'm doing this year.
Now I'm going back to hiding in my cave of finishing scifi bigbang so that my betas have a week to do their magic. I've only got 8000 words to get to the minimum. :/