Call of the Deep has content on the PvE and PvP sides, including the six-player Drowning Deeps heroic dungeon, the 6v6 Nova Core battleground, the return of the Blade and Soulmate season, and more legendary weapons.
The dev team gave players a heads-up on some rather extensive item changes that will impact weapons, accessories, and progression with legendary gear. This means that players can now select a PvE focus for Hellion legendary accessories, enjoy a reduced cost to upgrade weapons, and scope out some new instruments of death.
Source: Patch overview, dungeon overview, Official forums