Pantheon: Rise of the Fallen is a spiritual successor to such MMORPGs like EverQuest and Vanguard: Saga of Heroes. It is set in an open fantasy world of Terminus inhabited by all sorts of heroes, deities and enemies.
The story of Pantheon will unfold itself to a player gradually as he or she progresses through the world. The developer says that the game will be more of a sandbox-style RPG rather than your typical fetch-quest RPG. But there will be quests nonetheless, although it will not be that easy to get them in the first place.
It looks like the game will have a rather high level of difficulty, deep lore, and interesting gameplay mechanics.