In hindsight, it's surprising this issue didn't come up way sooner: it seems that the US Patent and Trade Office sent a letter to The War Z developer OP Productions (parent of Hammerpoint) and publisher Arktos Entertainment stating that the request to trademark the name "The War Z" has been suspended because it too closely resembles Paramount Pictures' upcoming movie World War Z (which is loosely based on the 2006 novel of the same name). The kicker: OP has apparently known about this for about six weeks, before it launched The War Z on Steam and removed all alpha or beta labels from its site.
Kudos to WarZScam and Redditors for spotting this legal development. The clearly anti-War Z site claims that not only is OP Productions legally vulnerable from the inevitable cease-and-desist order from Paramount, but it's also known since November 15th that it had no final claim to the name.
We of course had reservations about information of this nature coming from a website that obviously has a very pointed ax to grind, but the official documentation from the USPTO is much harder to dispute. None of us has spent a day in trademark law 101, but to the layman it looks like all of this is legit.
While we wait for the inevitable fallout, shall we discuss alternate names? My vote goes with The Walking DeadZ. That's not taken, right?