While Grinding Gear Games is keeping most of the details about Path of Exile’s big December content update secret (for now), the studio did announced that its title will be The Forbidden Sanctum. So you’re not allowed in there, case closed.
That isn’t to say that the studio is being completely mum about what’s coming for the game. Grinding Gear said that it’s changing up the Archnemesis system to encourage players to fight more monsters: “In the new system, we have added a significant pool of new rewards to rares, but the reward that is on the monster is hidden (and not associated with a specific mod), so you don’t know what kind of rewards you will get until you kill the monster.”
This change prompted so many follow-up questions that the studio compiled a chunky FAQ to deal with them. Another area of the game that’s seeing some significant work is the jewel system (which also got its own FAQ).
Source: YouTube