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
The below battlegroups are now linked for battleground matchmaking.
The below battlegroups are now linked within their group for dungeon finder matchmaking.
Phase 2 – Completed 11/3/10
Two additional battlegroups are added and all four are linked for battleground matchmaking.
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.
Final Phase – TBD based on performance of previous phases
We'll be updating this thread as these phases progress.