Yeah, they're in the dev diaries.
The new empowerment mechanic is at the core of the game's multiclassing as well. Every level you get 3 points of resource for that class and one "virtual" point for every other class, that you only get for real if you take a level in that class (eg. if at level 2 you have one level of paladin and one of druid, you'll have four points of each resource, but if you had two levels of paladin you'd have 6 points of paladin resource. Spending some resource on a spell makes it better, eg. if you spend wizard resource on the magic missile spell it fires five bolts instead of three. (You can have a max of two classes, can multiclass the NPCs as well but they have two "default" classes and at least one of their classes has to be one of those two, eg. Eder is Fighter/Rogue*, at level 1 you choose one of those two but at other levels you can choose any other class for them)
All abilities are per-encounter, but empower resource is refreshed on rest.
They're not using the health system though, they're using the wound system from Tyranny to encourage resting. (Pity, I kinda liked the health system).
I played White March quite late into the game, which made the difficulty much more manageable (also I was using Pallegina with St Ydwen's Redeemer, which could proc its Vessel-instakill on the eyeless). Also, I got everyone out alive which not everyone manages given how many kills there are in the CYOA sections at the end.
Also, they're changing crafting, mostly to emphasise using more different weapons not just upgrading the same ones forever.
*Eder was originally going to be the Rogue character in PoE, but was changed to Fighter to give the player a tank.