As we previously announced, we're in the process of rolling out region-wide battleground matchmaking. Once completed, all realms for our North American players will be matching together for battlegrounds, and four larger groups for dungeon finder use. This is a large technical undertaking, and while we're extremely excited to see this huge advancement in connecting players within World of Warcraft completed, the complexity means we'll be rolling it out slowly in a staggered approach.

Battlegroup listings and which realms are within each can be found at http://www.worldofwarcraft.com/pvp/battlegrounds/battlegroups/


Phase 1 - Completed 10/26

Battlegrounds
The below battlegroups are now linked for battleground matchmaking.
Whirlwind
Emberstorm

Dungeon Finder
The below battlegroups are now linked within their group for dungeon finder matchmaking.
Group A
Whirlwind
Emberstorm


Phase 2 – Completed 11/3/10

Battlegrounds
Two additional battlegroups are added and all four are linked for battleground matchmaking.
Whirlwind
Emberstorm
Vengeance
Bloodlust

Dungeon Finder
The below realms are linked within their groups for dungeon finder matchmaking. In the final phase, all realms are expected to be grouped in this manner.
Group A
Whirlwind
Emberstorm

Group B
Stormstrike
Nightfall
Retaliation


Final Phase – TBD based on performance of previous phases

We'll be updating this thread as these phases progress.