I don’t know what you guys did on your server to break them but Blizzard’s going to bust out some emergency maintenance before the weekend.
We will be performing urgent maintenance on the following realms beginning at 11:30AM PDT. The realms should be playable again by approximately 1:30PM PDT.
Aman’Thul, Barthilas, Blackrock, Caelestrasz, Dath’Remar, Dreadmaul, Frostmourne, Frostwolf, [...]

UPDATED! - All realms are now online and available for play. Thank you for your patience.

We will be performing urgent maintenance on the following realms to resolve a hardware issue beginning at 12:15PM PDT. We estimate that these realms will be playable again by approximately 2:15PM PDT. (src)

We will be performing urgent rolling restarts on the following realms to address issues with specific instances not starting properly. We apologize for any interruption this may cause in your normally scheduled play.
Each realm is anticipated to be down for no more than 20 minutes.
Arathor
Bonechewer
Dragonmaw
Eldre’Thalas
Firetree
Frostmane
Gurubashi
Nathrezim
Scarlet Crusade
Shadow Council
Shadowsong
Silvermoon
Skywall
Smolderthorn
Spirestone
Terenas
Windrunner[ Post edited by Drysc ]
(src)