That means alliance and horde players can join each other on their adventures. You can even join a guild created by a player from the opposite faction.
All perks exclusive to the alliance before the change to cross-faction are now available to both factions.

- Paladins of both factions learn Seal of Blood and Seal of Vengeance at level 64.
- Both factions auto-learn Riding at no cost when meeting the level requirement, and you'll automatically receive the mount in your backpack.
- Both factions auto-learn Riding at no cost when meeting the level requirement.
- Both factions shares quest items, with their party, while being in a group.
- Both factions earns 20% extra reputation.
Note: Alliance and Horde players can still attack each other in the open world if not in the same group.