It appears that in 5.4, the Timeless Isles zone will include, yet another weekly quest, with yet another currency, timeless coins. These coins can purchase pet costumes, some 'buff' items, and timeless armor.
These Timeless items appear to work in a similar fashion to the Latent Kor'kron Gear in Battlefield Barrens. You can transform a plain item into one with random stats that is appropriate for your spec. The Timeless isle items are ilvl 496 and so far do not have distinctive models.The beauty of timeless armor is that it appears to be BOA, maybe. Like Thunder Isle, I can see Elk running around the island doing the quest(s), then sending the spoils to my alts. This would allow a healer disc priest to replace all of her current crafted PVP gear for some appropriate 496 gear without having to learn to DPS!