I'm about done with all I want to do pre-patch, and what's left I'll get done tonight. So, after maintenance tomorrow, I'll be ready for a very different game. Rather than gush about it more, I'm going to post two videos. One is from Blizzard giving an overview. The other is from Asmongold about one of those changes, and how you can deal with it.
Blizzard: Learn the most important changes and new features in the Legion Pre-Expansion Patch.