I'd like to propose alternative outcome, if You don't mind. Kind on embracing cultural differences on elves too, and going more by way of political conflict.
Great Elven Civil War, and Rise of The Shadow Empire
Monarch: The Mad Empress
Capital Backbone Keep (former Galakrond's Rest)
Races: Void Elves (9%) - ruling class, and only full right citizens.
Nerubians (3%)
Faceless Ones (1%)
Undead (62%) - as slaves
Demon (2%) - as slaves
Other (23%) - as slaves
Regions:
Draginblight
Parts of Holwing Fjord
Azjol'Nerub
New locations: Pale City - former Nerubian temple complex, in the Old Kingdom
Government Type: Aristocratic Monarchy
History and Description: During many years of devastating elven civil war on the rule over their ancestral lands, Void Elves traveled to icebound lands of the Northrend, in search of ancient Nerubian knowledge from the long fallen Black Empire, and claiming much of them for their base of operations in Azeroth. In their vendetta against Quel'Thalas, they followed the path of the shadow magic further than any other race in Azeroth previous them, the more resistance they met, the more adjusted to achieve goals by force they become. And in this way, the Void found it's way into the Azeroth.
A warlike, and secretive society from the begging, dark elves have no counting numbers for the warfare, neither the labor force necessary to establish independence, after abandoning their human allies, no longer willing to support endless vendetta. In those times, they slowly started to enslave encountered races, and practice necromancy, to secure their inevitable victory in the endless conflict. They strengthen themselves in hatred for their southern loyalist brethren, whom they call usurpers, questioning right to the throne of the Teron Dynasty, and rejecting authority of Quel'Thalas. They cultivate resentment for their former human and elven allies, who chose peace, and call them traitors. In time, they forgotten much of the motifs once lead upon starting the war, as well as their exile, and foundation of new kingdom, and becomes driven only by desire for vengeance.
Once defeated, and forced to plot their vengeance deep in frozen saronite towers, now they again become increasing threat to inhabitants of Azeroth on both sea, and the sky, as merciless corsairs, and slave hunters.
Government: Under the sole and undisputed rule of the Mad Empress, endless web of intrigues and rivalry took place. The richest families never loose a chance to strengthen their position on the royal court. The most influential of them fight over seats in Empires highest state assembly - The Whispering Council.
Forest Elves exodus and founding of the Hidden Cities
Capital Vereesan Harbor - named after dead Elven Civil war hero (
)
Races: High Elves (72%)
Half-Elves (23%)
Humans (8%)
Wildhammer Dwarves (3%)
Draenei (1%)
Other (1%)
Regions:
Arathi Highlands, Hinterlands and mountains in between
New locations: Vereesan Harbor, build by once exiled High Elves, and strengthened by population of refugees from Great Elven Civil War.
Government Type: Federation of City States
After death of one of their previous leader during Graet Elven Civil war, new leadership of the last remaining High Elves decided withdraw from the conflict, no longer supported by human kings. They joined exiles, who traveled south of Quel'Thalas, and settled in few outpost, every of which give in time birth to the new city state - some located under the mountains, some hidden deep in the woods.
Remaining elves become isolated from their Quel'Thalas brethren, accusing them of using forbidden schools of magic, as well as rejected call of the Elven Empress, to continue the war, ant thus take on themselves her wrath. In time their distrust grown, they slowly started to explore new ways of living, rediscovering shamanic, and even druidic practices, learned from their allies - mostly Wildhammer Dwarves, and Draenei.
Government: Sorry, no current idea yet...
That's basically all. Fell free to comment. I'l be pleased to read what you think.