Patch 5.4 adds a quest line on the Timeless Isle that involves working for Kairoz of the Keepers of Time. He is on the Timeless Isle because the Bronze Dragonflight is not as powerful as it once was, only being able to catch furtive glimpses through time. He has created an hourglass that will allow for a window into the timeways, but you must collect 50 x Epoch Stones to make it usable.
After collecting the stones, you embark on a series of weekly quests to use the Vision of Time in different locations to calibrate the Vision of Time. Kairoz eventually will reveal that there is a traitor among the Bronze Dragonflight.
As the hourglass grows more powerful, he will send you to the Siege of Orgrimmar to look at one of the most devastating timeways you can find, which is the Hiddens Threads scene. This uses the damaged Stormwind Harbor area.
Next you are sent to to the Temple of the White Tiger to see a glimpse of Garrosh and Anduin, which is the scene you see below.