Ion Hazzikostas has already told us that the Timeless Isle, coming in patch 5.4, is meant to be a different sort of experience for gamers:
But that begs the question of what exactly we should expect on the Timeless Isle -- and, fortunately, Wowhead has come to assuage our curiosity with a look at the rare spawns and events to be found in this strange new place. So far they've found more than 20 rares as well as a number of events. The island has a heavy pirate focus, with plenty of spectral sailors as well as the ability to summon the Dread Ship Vazuvius and help the ghostly Tomb "Tom" Bone Apart find his body. But pirates aren't all there is on the Timeless Isle and, if we trust Hazzikostas about there being tons to do, we may find even more before 5.4 launches.