Blizzard has written a post on today’s extended Patch 10.0.5 maintenance.
Welcome back to World of Warcraft. We’ve deployed patch 10.0.5 and completed maintenance.Our maintenance period today ran a bit longer than we initially expected, but we made good use of it. We took the extra time to deal with some unexpected issues that can only be found and dealt with in the ‘live’ WoW environment(s).