The EU Datacenter for Guild Wars 2 has suffered a power failure that has "knocked out" some of the game's equipment. According to a brief post from ArenaNet's Mike O'Brien, this has resulted in having to "rebuild". EU accounts and NA accounts with connections to EU cannot log into the game. Regardless, today's update has been deployed. According to O'Brien, it was imperative to do so in order to prepare for this weekend's Path of Fire preview event.
We're working on restoring networking equipment. Once we do, we'll know whether we can safely bring up databases and game servers. At this time, we don't have an estimated time to restore service.
Today is release day. We're going to go ahead and post the release, although much of the world won't be able to access it until service is restored. I know that's far from ideal. But we have only three days left to prepare for the demo, and with that schedule, it's important that we get the release out today so we have time to deal with any issues that arise. I appreciate your understanding.
You can check out the full post on the Guild Wars 2 Facebook page.