Arenanet has just posted an announcement stating that the Guild Wars 2 servers will be offline on February 13th 8:00 - 12:00 GMT. It will be routine server maintenance.
We will be doing scheduled server maintenance on Wednesday February 13th from 12:00 AM – 4:00 AM PST (08:00 – 12:00 GMT). During this period players on both North American and European worlds will not be able to log in. Forums, register.guildwars2.com, and buy.guildwars2.com will also not be available during this time, and the Black Lion Trading Company will not be available until 6:00 AM PST (14:00 GMT).