If you're like me then you have been waiting for this client with bated breath since the announcement that it was on the PTR. Today 1/31/2012 WoW Patch 4.3.2 was released which has a handful of changes and fixes, it also provides support for a 64-bit version of the wow client.
[Note] : I do not take credit for this guide or the links. Original post is by Adam Holisky at Joystiq. The article is here
To do this you must have your WoW Patched to the latest version. These are the official wow files but they didn't come bundled with the patch so you have to download them independently. Windows Client and the Mac Client.
For both Windows and Mac you need only to download the Zip file and extract the contents into the root of your wow folder.
Ex; C:\World of Warcraft\[Battle.net-64.dll, MovieProxy.exe, WoW-64.exe]
Windows
Battle.net-64.dll
MovieProxy.exe
WoW-64.exe
Mac
World of Warcraft.app
- Once you Have completed that you need only to start up the launcher.
- Go to upper left click 'Options' -> 'Game Preferences' and make sure 'Launch 32-bit Client is unchecked at the bottom.
- If this option is greyed out or does not work then close the launcher and 'Right Click' -> 'Run as Administrator.
Note: This works for all versions of 64-bit Windows and 64-bit Mac OS.
Enjoy and have fun utilizing more than 4Gigs of ram and about a 13% performance increase on average!
[EDIT]: The servers now recognize the 64-bit client as authentic and working FOR US and EU
Post on Official Forums about the status