Blizzard has released the 64-bit client (Patch 4.3.2 build 15211) for Windows and Mac OS X for Live servers. Looking through the first few pages of the forum post, most reviews are positive, as would be expected. The client will only work with Patch 4.3.2 32-bit client already installed. On 14-Feb-2012, an updated 64-bit client (Patch 4.3.3 build 15314) for Windows and Mac OS X was released to match the PTR update on 18-Feb-2012. On 22-Feb-2012, links for build 15338 were updated on the PTR 64-bit client forum page and then to build 15354.