What Zephras Isle is
Zephras Isle is a floating island high above Azeroth and the new starting zone for the Skyborne. Blizzard described it on stage as wooden docks in the clouds, with ships moored to stone spires by chains — architecture that visibly borrows from Skywall, the elemental plane of air.
The island covers levels 1 through 12. Every Skyborne character starts here, regardless of whether the faction choice landed on Horde or Alliance. From there the journey continues into the familiar zones of the Eastern Kingdoms and Kalimdor.
The pact with Skywall
The Skyborne descend from Highborne exiles who struck a pact with the wind spirits of Skywall generations ago. That pact is not background flavour, it is the conflict of the zone: part of the people holds to the elemental tradition, another considers the arcane legacy of the ancestors — or something darker — the better path.
This is exactly what the faction choice at character creation hangs on. The Windshaper side joins the Horde and unlocks Shaman, the High Order joins the Alliance and unlocks Mage. Both share an ancestry but, in Blizzard's words, "no longer share a common vision for the future."
What makes the starting zone notable
Zephras Isle is the first entirely new starting experience in years and the first one that is not on the ground. The Skyborne bring their own racials, voices, dances and customization options; druids get dedicated Skyborne forms.
What to know before you plan
The race and its starting zone are not part of the plain subscription. They require at least the Skyborne Heroic Pack — a point that drew considerable criticism after the announcement, since WoW: Forever is otherwise explicitly included with a subscription.
Still open
Blizzard has not given a quest count for the island, nor said whether Zephras Isle keeps a role past level 12. Nothing official exists yet on reputations, professions or a possible endgame connection.