There seems to be quite a few people who enjoy zombie apocalypse RP's here, myself included, so numbers shouldn't really be an issue. I'd need a lot more information before I commit though. Firstly would you plan on the RP starting near the beginning of the outbreak or some time in? What country would it take place in? U.S, I imagine, but worth knowing for sure. Also might be worth noting what writing level you're looking for, since there's likely to be love for zombies in all of them. Mostly though if you have a plot idea I'd get it down. People will be a lot more willing to commit if they have a detailed and interesting idea of what they're committing to.