Patch 6.2.4 is now ready for testing testing on the Public Test Realms (PTR). Participating on the Public Test Realms lets you test a patch before it has been released on live realms. If you'd like to help test and provide feedback, you can start by copying your character and downloading the PTR client. Once you've had a chance to try things out, visit the PTR Discussion forum to discuss the patch. To report issues or errors, use the in-game Submit Bug feature (found under Game Menu -> Help -> Submit Bug) or by visiting the PTR Bug Report forum.
 

World of Warcraft Patch 6.2.4, PTR

Battle.net Infrastructure

• Client support for Battle.net infrastructure changes, including some memory optimizations.