The update lets players explore the continent of Val Oriyn, an isolated 'lost world' filled with "savage jungles, colossal ruins, and the undiscovered homeland of the barakas." This is a baraka. In beach-wear, naturally.
You can check out some gameplay and plot details for Fate of Arun in the trailer above, but there's also a hpretty in-depth look at what to expect over on the Tera website. Four new dungeons contain all the hack and slash co-op looting you could want, while the new PVP Coliseum adds a vaguely MOBA-esque team-based arena mode.
You'll also find a simplified enchanting system, the ability to fuse crystals into improved versions, and a streamlined and improved quest interface. For the real nitty-gritty, you can check out the in-depth patch notes here.