The years of peace have cause several of the factions to drift apart.
The Forsaken have either died off or finally devolved into madness.
The Blood Elves and High Elves have reconciled their differences. No longer part of the Horde or Alliance, though they have decent relations with both. The Deadscar is no more, their Rune Stones are up and running, and the elf Gates are better than ever.
The Tauren have long since opened dialogue with the Taunka and Yaungol. Thunder Bluff has become a capitol representing each of these peoples. Tauren architecture more closely resembles Taunka architecture. Thunder Bluff has been fortified by the Yaungol's expert use of fire and oil.
Vol'jin is near death (trolls are said to have pretty shot lifespans), but he accomplished much for the Darkspear in his time. He had brought many trolls to his side prior to he Siege of Orgrimmar. Using these numbers, he went on to bring together all the other Jungle Troll tribes and socialize them to the new norms of Vol'jins tribe. Together, they fully repair Zul'Gurub. Taking from technology from the other tribes scattered around Azeroth, they made it nearly as advanced as most other cities. Once stabilized, he answered the call of the Revantusk, aiding them in either bringing the other tribes into the fold or putting them down. They take over Jintha'alor and make it into a Forest Troll capitol. As their power grows, more and more Amani leaves Zul'Aman to join them until there are only radicals left amongst the ruins. Vol'jins son and heir, Sen'jin, has begun the long process of repairing relations between troll and loa.
Rexxar, has brought together a powerful faction of ogres comprised of the Mok'nothal, the ogres of Ogri'la, Lantrasor and his clan, as well as the scattered tribes of Azeroth. Rexxar's need to protect and establish themselves as a power is derived not only from his advancing age but also the death of Misha. The Ogri'la ogres enlighten heir brothers and aid in building a surprisingly advanced home for themselves.
Following the Siege, the orcs had gone through a great cultural upheaval. No longer did the taste of war appeal to them. Many powerful and popular orcs backed off and claimed the status of clan head of the various clans. Thrall, by default, led the Frostwolves, Jorin Deadeye leads the Bleeding Hollow, Ariok has risen to prominence and takes control of the Blackrock, Gordul continues to lead the Shattered Hand, Zaela continues to lead the Dragonmaw, Mankrik has returned to the Warsong and leads in the stead of the Hellllscream lineage. The Burning Blade, being so few, joins the Warsong. In order to keep the tribes together, Thrall forms a council with each of the clan leaders. The Frostwolves have relocated to Winterspring, driving out the demons there and establishing themselves. Durotar has been irrigated and is now a lush farmland.
The Bilgewater has fallen under new leadership. It is a new named goblin who actually follows the storyline played out by players. Policies have become more eco-friendly since Garrosh was taken out.
In order to ensure another Garrosh never plunges the Horde into chaos again, Vol'jin, the Warchief following the Siege, and the other leaders chose to establish a Klaxxi like organization who would rise up against the Warchief if his or her ideals go against the ideals of the Horde. A champion from each race within the Horde is chosen to lead this organization. Nazgrel was chosen to represent the orcs, Tagar for the Tauren, Patch for the Goblins, Rokhan for the trolls, and Lantrasor, although half orc and half draenei, was chosen to represent the ogres.