Patch 7.3.5 comes out tomorrow. I've been really impressed with Blizzard's release discipline this expansion. Each patch has come out like clockwork 11 weeks apart. Amazing job by the team, especially the project managers.
Now hopefully they can bring Battle for Azeroth in with the same discipline.
Patch notes for 7.3.5 can be found here.
From the notes, it looks like this patch is all about revamping the mechanics of the leveling game. Level scaling is being introduced everywhere, and there look to be lots of changes to improve that part of the game. I think it's about time. Out-leveling a zone while you're still questing in it is annoying.
The other part of the patch looks to continue to the story in Silithus. It will be interesting to see how the denouement of the Legion story plays out.
There's no mention of the Allied Races, so I imagine that they are saving them for BfA, or possibly as a pre-order unlock.
Finally, if you have authenticator, 4 extra bag slots! Blizzard CS even got in on the latest meme: