As recently discussed in our WoW General forum thread Help me choose a realm to prepare for WoD + community events, we have officially chosen two servers in the same Cross-Realm Zone (CRZ) block to host both an Alliance guild and a Horde guild called Multiboxer.

Our Alliance guild is on Sargeras, and our Horde guild is on Bleeding Hollow.
Here is the current list of US Realms connected to these two:
Sargeras
Illidan
Bleeding Hollow
Arthas
Black Dragonflight/Gul'dan/Skullcrusher
Auchidoun/Cho'gall/Laughing Skull
Azgalor/Azshara/Destromath/Thunderlord
Deathwing/Executus/Kalecgos/Shattered Halls
Blackwing Lair/Dethecus/Detheroc/Haomarush/Lethon/Shadowmoon
Alterac Mountains/Balnazzar/Gorgonnash/The Forgotten Coast/Warsong
Agamaggon/Archimonde/Jadenar/The Underbog
Andorhal/Scilla/Ursin/Zuluhed
Burning Legion
If you make a team on any of these servers, you can probably join our guild, and/or join us for world PVP and dual-boxing.com community events!

See the following post for more information:
US PvP - (H) Bleeding Hollow - (A) Sargeras - Multiboxer: Dual-Boxing.com's "Multiboxer" Guilds looking for more!