Prompts have been organized at untold_legends so everybody should run over there and look at what you might do. Because so many got offered, more than there are participants, there isn't any actual formal claiming. Basically, if you want to create something for a prompt, all you have to do is leave a comment on it and say what you're going to do. Then on March 29, you check in if you're done to claim a date for posting. Very casual and easy. Plus, fic only has to be 1k. How can you not want to take part?
AND, if you don't want to create something for one of the prompts, you can always write something of your own. Considering 90% of what I do is non-M/A, B/C, you can bet I'm going to have multiple works for this. I have 9 of those prompts I mentioned the other day that fit, and there are seven new prompts at untold_legends that tempt me. I would love to have at least two done, one from each group.
Considering I'm going to be working on my Mithian/Percival for merlinreversebb as well as all the original writing deadlines I have, I'm probably insane, but oh, it's a good kind of insane.