Much of the content we've seen in Guild Wars 2 has been focused on advancing the living story. We've seen significant game features added as well, features like custom arenas, WvW progression, guild missions, and spectator mode, but much of the new PvE content has been related to the living story. ArenaNet wants the narrative of their lush virtual world to evolve and change over time, and therefore, many of its content additions have been temporary, exiting the game when the story arc has completed its course.
Feedback on the limited-time content has been mixed. Some players argue that this approach makes the experience special because rewards like titles, achievements, and skins are gleaned only during these events by those who played at just the right time. In other words, scarcity, value, and basic economics. Others don't enjoy seeing their favorite content, like the Super Adventure Box or Molten Weapon Facility, removed from the game after only a short period of time.
Fortunately, ArenaNet is listening to the feedback; Colin Johanson has given us an update about how the studio plans to tackle content in the second half of 2013. For more musings on this topic, watch this video edition of the Flameseeker Chronicles and chime in with your thoughts in the comments section below.