Diablo III Patch 2.4.3 Released

The time has come to return to Tristram and take on the original Diablo, as proclaimed in this announcement heralding the availability of Patch 2.4.3 for Diablo III. Apparently the 20th Anniversary Event will only be available during the month of January, so there's only a limited amount of time to check it out:
New Feature: 20th Anniversary Event

A mysterious group of Cultists is stirring up trouble! Hunt them down in Adventure Mode to uncover clues that reveal a portal into Tristram’s past, and rediscover the terrifying darkness that took hold of the town so many years ago…

- This event is only available in January

Please note that future anniversary events will feature a pre-cursor event available from January 1-3.
And the 64-bit client is now the default on Windows 64-bit operating systems, so you just might get a performance increase, to boot.