For posterity, here are the patch notes associated with the early access release. Might have some minor spoilers if you're wanting to go in blind.
Added a new area, Iresborough - this new location can be accessed from the Traitors' Respite. Go past the waterfall to find it.
Added a new weapon, the Vilirihn Crossbow - found in Iresborough.
Added a new boss! Also found in Iresborough.
Added a merchant mechanic. Complete a short quest in Iresborough, then return to the Traitors' Sanctuary.
Added ten new Runic Powers!
Updated the Auranum Keep.
Updated the Traitors' Sanctuary.
Updated how NPCs search for a target they can't navigate to.
The developer console is now disabled by default. It can be enabled in the options menu.
Adjusted NPC AI to improve performance.
Updated the Enforcer's model.
Gave the Enforcer a ranged attack.
Improved ledge-checking when walking into small ledges that boost the player.
Increased the minimum and maximum values on the brightness slider in the options menu.
Made the player slightly taller.
Improved performance when loading areas.
Improved various enemy attack animation speeds and hitbox timings.
Updated models to have a smoother look.
Breakables (barrels, crates) now react to damage when hit.
Corpses can now be hit and gibbed with projectiles.
Gibs no longer block projectiles.
Area names now only appear once upon entering the area.
Updated various sound effects.
Improved NPC pathing so they will be better at navigating around other NPCs.
Slightly reduced the firing rate and damage of the Lunar Focus.
Spider webs can now be broken by attacking them.
Updated runic power icons to be more unique.
Changed "Ermosar's Runic Blessing" to require 4 slots (from 2).
Changed "Skrillhaven Compartment" to keep 8 runeglass on death (from 5).
Changed "Scavenger's Spoils" to require 3 slots (from 2), and increased the speed reduction.
Updated the runic power equip menu.-
Fixed an issue that caused the player to take too much damage when hit by certain damage triggers.
Fixed a section in the Auranum Keep that would cause the player to fall through the level.
Fixed an issue causing the brightness setting in the options menu to reset.
Fixed runeglass spawning from crates or barrels spawning again if the level is reloaded.
Fixed UI not fitting correctly on the screen for ultrawide resolutions.
Fixed an issue where an interaction prompt would stay on the screen even if the player had left the interaction.
Fixed gibs sometimes acting like they were submerged in water, even if they weren't.
Fixed an issue where the lighting settings for an area would load instantly as soon as the area loaded.
Fixed the player's death camera sometimes being able to get out of bounds.
Fixed an FPS drop occurring on medium graphics.
Fixed various issues with rebinding controls.
Fixed formatting of certain refresh rates in the options menu.
Fixed the player getting emyrill armor when resting with the "Altarkeeper's Gift" runic power.
Fixed automatic weapons continuing to fire after the player respawns regardless of input.
People are already finding bugs... Should have a small patch out soon!