Yeah, basically they put up giant walls around New York, and just toss everyone in there. Or at least, it was NY in the movie, it wouldn't have to be in the RP.
Another RP premise I thought could be fun, is the aftermath of a zombie apocalypse. Since we've all seen what being -in- the apocalypse is like, what if there was a setting where the global pandemic happened, most people died, then eventually the zombies just decayed and died off? So most of the population would be gone in this world, and the biggest threat would be the other humans, not zombies(There would still be a few left). And maybe everyone could be infected with the virus, so when you die, no matter the causes, you turn into one. Even if it's old age, or just being killed by another person. So burning bodies would probably be popular there as well.
Anyway, either RP sounds good to me, I've talked with Aeliss quite a bit about both.
Oh, and of course you're welcome to join Cold Secrets if you so desire =)