I was playing PZ for the first time today, and whilst I was wondering around aimlessly from house to house I was thinking about how fun a multiplayer would be (I'm always a fan of multiplayer zombie games, of the opinion that the zombie genre is practically made for teamwork), and thought it would be interesting to have a multiplayer game mode in which the objective is to eliminate all 3566-ish zombies that would be roaming around Muldraugh, or something to that effect.
I'm not sure how the zombie populations are distributed by the code, so don't know how feasible it would be (also 3,500 kills would take a while for a handful of people), but wanted to know how other people felt on the idea, or any extrapolations of the concept.