As previously announced, we are working on implementing Cross-Language Battlegroups (CLBG) to increase the size of most Battlegroups. You can find the original announcement here: http://forums.wow-europe.com/thread.html?topicId=6425923570

The CLBG is currently open for testing on the PTRs, allowing players from the different PTRs to meet each other in the Battlegrounds and Arenas. This weekend we will be doing some focused testing of the Battlegrounds, and we will appreciate it if you could participate during these times:

On Saturday 28th of March, focused Battleground testing will take place between 18:00 and 20:00 CET
On Sunday 29th of March, focused Battleground testing will take place between 16:00 and 20:00 CEST (remember to adjust the clock!)

We will be thankful for your feedback about any bugs and issues encountered during the focused testing, and we will be especially interested in hearing if players from another PTR join a Battleground on the same side as you.

Please post test reports and feedback here:
http://forums.wow-europe.com/board.html?forumId=11091