They just pushed a new client update. Soon.
I'm continuously amazed at the amount of salt that is generated every single time there's a major patch. This is not unusual, and it's not even that bad, even if it extends into Wednesday. Cross-faction play is a MASSIVE change to how the game functions, and no doubt there are any number of impossible to foresee complications with something as complex and deep as 16+ years of game code on top of a very old engine. I'm sure much of the Blizzard CS staff would be happy to not have to work grueling overtime on this, and am reminded to be grateful for all the work the engineers put into providing a stable gaming experience for us.
IT'S ALIVE!111
My advise at this point, go to bed and get some rest .... wait to see what Microsoft has to say/do about it :-)