I'd potentially be interested in this, based on how much free time I have and whether or not I can think of a character.

Personally, I'd like to see a story that was a little smaller in scale; something that didn't drag our characters into the huge events that happen during the novel. Maybe we could write something based around a significant but still somewhat local event; like if we wrote about what happened at one of the quarantine sites that led to the towns being abandoned after villains took over, or about a local villain war started in the aftermath of a big player or players being removed (like the Boston games), or a new villain arriving in town and making a big splash (maybe even a cell of the Elite looking to take over). Something with a focused plot and a small cast.