In the storytelling (lore if you will) we are getting explained how Horde & Alliance have to put the battle between them to the side and join forces to overcome a greater evil.
How about you show us this in-game in the form of being able to actually join forces in PvE content. such as dungeons and raid scenarios. As of now when you search for people in the dungeon/raid finder you are actually only looking at half of the potential playerbase.(half is not accurate due to horde/alliance dominant realms, but you get my point).
I myself only focus on the PvE aspect of the game. I play on a horde dominant realm. with wm off and I can easily play a entire week without even seeing a player from the opposing faction.
In the early years of World of Warcraft faction identity needed to be a thing and the war between the sides was a big matter. But as the expansions are rolling this war is just a weak memory and not a present issue.
I strongly suggest the right direction to go is to implement cross faction dungeon and raid!
I am well aware of making this happen will upset alot of the playerbase, but if you are able to see the greater picture, World of Warcraft is no longer about wich faction you choose, and thus it should not be such a weighty choice if you roll dwarf or blood elf!
TL:DR - Let us play together, let us pick players from the entire community and not slice the playerbase in half. It is about time Red and Blue join forces!