Then again, we might be lucky and they'll be back in ten minutes. Who knows with these things? Keep an eye on WoW.com and we'll keep you posted should we hear anything. If you're not sure if you're part of one of these battlegroups, the full list is behind the cut.
Update #1: Blizzard is aware of the issue. Not much else at the moment.
Update #2: Looks like most servers are coming up. Our poor friends on Quel'Dorei are still down for the count.
Update #3: Maintenance on these realms not necessarily 'done' says Malkorix.
Update 11:57pm: Both battlegroups went down 12 minutes ago. More as we know it.
Update 12:18am: Blizzard says they are working on it and that any compensation will come after the problems have been resolved.
Update 3:37am: The servers are up temporarily, but will be intermittently taken down while they continue to resolve the underlying problem.