So the book comes out next week. I'm not interested in the setting as a resource, though I would expect to read it for general enjoyment. What will motivate a purchase from me is raw rules crunch. So what are we expecting?
New spells, 2 new subclasses, new magic items and rules to govern them. New monsters, probably including the Moorbounder, the animals the Mighty Nein ride across WIldemount when not using teleportation circles. The spells will largely be Dunamancy, spells that manipulate time & space for some pretty cool effects.