Patch 3.4.3 becomes available the week of October 10, bringing with it a variety of updates to Wrath of the Lich King Classic including:
Engage in twelve encounters across five wings within the Lich King’s stronghold when the Icecrown Citadel opens its doors on October 12 at 3:00 pm PDT (22:00 GMT) globally. Players can undertake the challenge of this raid dungeon in either Normal or Heroic modes. The Shadowmourne Legendary quest chain will also be available to Death Knights, Paladins, and Warriors who believe they have what it takes to wield this legendary two-handed axe.
Read the Wrath Classic 3.4.3 PTR development notes to learn more details.