All PC servers will come down
tomorrow, Wednesday, March 25, at 6:00 AM PDT / 1:00 PM GMT for the new game update and Emerald (US East Coast) server hardware upgrades. Downtime is expected to last up to 6 hours for Emerald, and 4 hours for all other server regions.
Full patch notes can be found on the forums
here.
Source: Official News and Announcements
