"World of Warcraft servers taken down for maintenance and client patch 3.1.0 rollout. Outage clocked at more than 16 hours. National productivity increases by 10%."
It seems as though Blizzard's methodology for maintaining their World of Warcraft servers is to take them offline early Tuesday morning (often around 1:00am or 2:00am Pacific time) and to keep them offline until between 9:00am and 11:00am. During the client patch 3.1.0 rollout they took the servers offline at 1:00am and, at the time of this writing, don't have them back online yet. Instead there is a message on the client login screen indicating that "there were problems found in testing" and "we'll try to have the realms back online in the next two-to-three hours."
I'm installing that phenominal time-sink World of Warcraft (I actually have legitmate reasons for doing this ... honest). So far I have watched it download patches and updates for TWO FRICKEN HOURS. And without telling me, WoW decided to download all these many megabytes of patches over a BitTorrent system. This got me a nice lil' nastygram from my ISP (my ISP prohibits torrent traffic for technical reasons).