For once we have news related to The War Z that isn't their fault. Well I suppose not entirely. Over the last few days including today they've been getting bombarded with DDOS attacks on their servers bringing them down. So now we've gotten a response from their Community Manager via the forum,
"Guys over the last few days we have been under attack by various forums of malicious attempts to shut down our servers. First we were hit with an attack that would rest our DNS IP so that you could not connect. This was solved a couple days ago early in the morning but took time to actually resolve world wide once the fix went in.
This morning we are being hit, again, with a DDOS attack on our login server. We are implementing additional counter attack solutions and how to have this resolved asap. Unfortunately with these types of attacks it is very difficult to give a good time frame of when it will be resolved." - Kewk