We are aware of reports of high latency on some realms, and are currently working hard on a solution to this issue.

Please post on the following thread if you are experiencing these issues on any of the below listed realms:
19/06 - Latency & Disconnection Report Thread

Auchindoun
Ghostlands
Hellfire
Karazhan
Nagrand
Shattered Halls
Sporeggar
The Sha'tar

We thank you for your understanding and your patience in this matter.