Originally Posted by
Kathranis
Actually, the South Seas and the Maelstrom region (which already technically has its own 'continent' level map in-game) have plenty of zones.
Speaking hypothetically, here's a listing of confirmed, named zones that could appear in a South Seas / Maelstrom / Naga expansion. Several of these come from the same sourcebook that introduced all of the zones in Northrend for the first time.
Kul Tiras: Confirmed to have drifted further into sea as a result of the Cataclysm. The capital of Kul Tiras, Boralus, could serve as an Alliance hub. Also included could be the smaller islands of Crestfall and Zul'dare.
Kezan: Only Bilgewater Port, the northenmost city on the island, has been seen, and Blizzard indicated they'd like to someday revisit it. It houses the massive goblin city of Undermine, which could serve as a Horde hub. Also known to contain the port city of Edj and a troll settlement, Voodress Village.
The Broken Isles: A chain of islands that include the ruins of the night elven city Suramar and the Tomb of Sargeras, as well as Stormreaver Bay, where Gul'dan made his base during the search for the Eye of Sargeras, and Balor, an island stronghold established by Stormwind during the First War.
Zandalar: Home of the Zandalari, birthplace of all troll civilization. Ruled by the Rastakhan and the prophet Zul. It began to sink beneath the waves as a result of the Cataclysm, but Blizzard has confirmed that it's still around and that the Zandalari won't be stopped until their leaders have been dealt with.
Tel Abim and Plunder Isle: Small islands occupied by trolls and pirates, respectively.
The Rift: The remains of the original Well of Eternity, a massive rift in the ocean floor. It's connected to the Elemental Planes and is heavily implied to have connections to the Rift of Aln in the Emerald Dream. It's also home to Nazjatar, the massive naga capital which was built from the ruins of Zin-Azshari.
The Boiling Terrace: An underwater region housing thermal vents and underwater volcanos, with boiling and acidic waters, to the southeast of Nazjatar.
The Drowned Reaches: Located on the edge of the Boiling Terrace, a massive graveyard of ships torn apart by whirlpools, populated by the ghosts and reanimated corpses of sailors and pirates.
Gishan Caverns: Located to the north of Nazjatar, a massive network of caverns in the ocean floor, occupied by monstrous sea creatures.
Pillar Deep: A region to the northeast of Nazjatar, home to thermal vents and vocalnic fissures, as well as giant stone pillars and massive tubeworms.
Scintal Reef: A massive coral reef to the southwest of Nazjatar, populated by makrura and home to their primitive, tribal capital, Makrura.
So, there, 12 potential zones which can easily be paired down to the standard 7-8 of an expansion, with possible alterations to raise some landmasses to the surface, so as to not make it so heavily focused on underwater content.