Kotaku has word that The War Z is no longer sold on Steam just days after the zombie survival game was added to some outcry (thanks nin). They have a statement from the game's developer: "We're making sure that our Store page is 100% correct this is why," Sergey Titov tells them. "Bottom line – our end goal is to have satisfied and not angry customers, so this is more important for us than everything else." Here is the explanation they received from Valve:

From time to time a mistake can be made and one was made by prematurely issuing a copy of War Z for sale via Steam. We apologize for this and have temporary removed the sale offering of the title until we have time to work with the developer and have confidence in a new build. Those who purchase the game and wish to continue playing it via Steam may do so. Those who purchased the title via Steam and are unhappy with what they received may seek a refund by creating a ticket at our support site here.