It comes idea, where You can have 4 sets which is included gear and build together. So 4 sets is will be: PvP gear and build, Dungeons Gear and Build, WvWvW gear and build, PvE gear and Build. You can switch set when you are in city (like Human, Charr, …), when you are near entrance to dungeon, in WvWvW entrance city, and in PvP entrance island. So it will makes easy and fast way change gear and build. Also it will be better organize and collect gear for each set.