Shouldn't there be some sort of plan for when the world gets taken over by zombies? I mean sure. It is great to maintain a stock of supplies for immediate survival--food, toilet paper, water, ammo, etc. But when those supplies are exhausted and you are craving human contact with someone other than the undead, what do you do?
Zombies don't typically have the capacity for rationalization, so I don't think it unwise to develop a contingency plan in advance for where society should be reestablished by the living that remain. Walled cities seem like the logical choice, but we are suffering for a lack of those in the United States. And the likelihood of international travel to a locale where a walled city is an option is not very realistic.
An island or peninsula seem like good second choices. That is unless Max Brooks is right and the undead can survive underwater and easily come ashore to feast upon our brains. In that event, perhaps an island with a sea wall of some sort like Galveston perhaps.
At any rate, having a well established plan in place in advance is not a bad idea--one that society as a whole is aware of. Who knows? It might come in handy for other situations such as in the unlikely event that human intelligence diminishes to the point that Sarah Palin is a likely shoe-in for the White House.