In World of Warcraft, the Horde and Alliance have been fighting long enough. In the most recent cinematic, they are literally fighting alongside each other. Why do we as players have to continue fighting each other, especially considering they've saved the entire world repeatedly. Now that they're fighting even bigger enemies, they need to end this and make it so Orcs can walk into Stormwind and Humans can walk into Orgrimmar. They also need to be able to fight alongside each other in the upcoming raids against the burning legion. If the actual leaders of the factions are doing it, we as players should also be able to.

As far as PvP, keep it the same. In Rated Battlegrounds sometimes you fight Horde vs Horde or Alliance vs Alliance already. Either keep it Horde vs Alliance or make it anyone vs anyone. It would help balance sides and make battlegrounds more fair. World PvP is already dead, no need to make changes there. Raiding major cities also died on a majority of servers because most servers are mostly Horde or mostly Alliance. If anyone misses it then let them have a free transfer to a server where this change isn't implemented.

I understand it's been a core part of the game since launch but really nobody is play World of Warcraft to intentionally be split into 2 different groups. Many old players would return just to see what it's like to go into raids with both sides or join guilds of the opposite faction. Old raids that operate differently based on your faction like ICC could either be based on how many of each faction are in your party or it could be an option like difficulty is when you right click your portrait.

It might not be easy from a developers point of view. But what seems like a small feature would change the entire game for the better. 12 years is longer than a majority of real life wars. We didn't start this war and we don't have an option to end it. But Blizzard has that power and they aren't aware that we want it to be over.