Gilneas is set to be introduced in the Cataclysm expansion, as the level 1-12 starting zone of the new playable worgen race. Players enter the story as a human. The quests will teach them how the worgen curse came to be, how the humans of Gilneas came to be affected by it and lastly with the player him/herself being infected with the worgen curse. Further on there will be the shattering of the Greymane Wall, which forces the Gilneans to re-enter the conflicts they sought to escape.
The threat of Forsaken attacks, and an offer of aid from the night elves brings Gilneas into the Alliance, which serves as a counterpart to the introduction of the Horde-allied Goblins of Kezan. In-game, Gilneas appears to be a dreary and rainy territory, reflecting the cursed nation itself. The Greymane Wall will receive a graphical update to match the new style of Gilneas (a Victorian style).
While Greymane's efforts to stem the tide of the Scourge kept Gilneas from the grasp of the undead, the Greymane Wall inadvertently subjected the Gilneans to a dark fate all the same. They fell under the worgen curse as did their neighbors to the north in Silverpine. Somehow, the Gilneans freed themselves of the curse, to some degree. Though not under Arugal's thrall, the people of Gilneas were still transformed into the monstrous worgen.
No one had seen a Gilnean for more than ten years until the Cataclysm, where it was discovered that they have been transformed into worgen, but have somehow retained their will. Driven by their curse and threat from the Forsaken, Gilneas was finally driven into the Alliance's fold.
Gilneas' current state is partly unknown. Genn Greymane appears to still be alive, as he is among the first NPCs encountered by worgen players, administering a treatment for the worgen curse.
What is known is that worgen citizenry have escaped their curse's iron grip. However, Brann Bronzebeard 's rumours about the Naga have not been proven untrue.
One of the new battlegrounds in Cataclysm will be called Battle for Gilneas, likely featuring the ongoing siege of Gilneas by the Forsaken.
Outside the battleground, Horde players are sent into Gilneas from quests in Silverpine to stop the worgen and fortify their hold on the kingdom.
The human kingdom had supported the Alliance during the Second War, but King Greymane had no qualms about severing all ties to the outside world when it became clear that the Alliance needed Gilneas more than Gilneas needed the Alliance. Unbeknownst to the rest of the world, darkness fell on
Gilneas after the Greymane Wall's gates had been closed, and the worgen curse ravaged the nation. Before long, Gilneans were fighting against Gilneans in a bloody civil war that left the kingdom in tatters. Remarkably, the people of Gilneas have somehow managed to hold on to the last vestiges of their humanity... for now.
Gilneas is a large peninsula that juts into the sea south of the western regions of Lordaeron. Silverpine Forest lies to the north-east and Kul Tiras and Crestfall await across the sea to the south and Tol'Barad stands to the east. Because of its nearness, Zul'Dare is considered part of Gilneas.
Gilneas is a cold, rainy place, mainly because The Great Sea surrounds the peninsula on three sides, making sea storms common. High cliffs on the shores protect Gilneas from sailors’ curious eyes. The Greymane Wall is the only evident site in Gilneas.
Preliminary dialogue from Cataclysm has revealed that Gilnean mages and healers went to great strides to fight the affliction.
Gilneas has undergone deep changes in the wake of its cursing, and while the people maintain their free will, the impact of the curse remains to be seen.
The forsaken, led by Dark Ranger Thyala, have begun an invasion on Gilneas.