The next World of Warcraft patch, version 7.3, is already on the PTR and it may contain hints about the game's next expansion.
Patch 7.3 is believed to be the game's last before this year's expansion releases. Blizzard hasn't announced the name of yet, of course, but you can be sure there's going to be a World of Warcraft expansion later this year.
Stalwart dataminers at Wowhead managed to dig up a few references to the next expansion's setting from a particular piece of armour.
Called Kul Tiras Quest Armor, this quest armour set is named after the country led by Lord Admiral Daelin Proudmoore in the Second War. There are eight icons that make reference to this set in the game's database, and they all use the same naming scheme Blizzard used when naming quest gear in previous expansions.
"Zooming in on the side armor on the skirt, we can more clearly see a map to a new zone, as well as some tentacle decorations underneath," the post points out, speculating that Kul Tiras could be a possible location in the next expansion.
This may mean that the next big expansion, or possibly patch (though unlikely), will involve the Old Gods somehow and the reemergence of Kul Tiras. This is obviously all speculation at this point, but it's something WoW fans are very excited about.