As Mists of Pandaria progressed, and the Alliance complaints about "Horde favoritism" got louder, I bet there were some Blizzard developers looking on with dismay. Unlike the rest of us, they knew that the upcoming expansion--with production already in full swing--was Horde-centric, dialed up to 11.
After the WoD reveal, I think that even the most die-hard Horde supporters have to concede that the Alliance has a point about faction focus in the storyline. Still, hopefully there will be some interesting elements about the Draenei and some paladins running around smiting orcs.
As for the expansion topic itself, eh, it seems okay. Instead of time travel, it's probably easier to think of it as a "Mirror Universe" version of Draenor.
The one thing I am a bit concerned about is that Blizzard seems to be focusing on their core properties a little too much lately. Hearthstone is Warcraft-skinned. Heroes of the Storm uses the Warcraft/Starcraft/Diablo universes. Now WoD hearkens back to the original Warcraft games. Admittedly, it does come after Mists of Pandaria, which ventured into a new direction.
Nostalgia is all well and good, but sometimes you need to look forward, not backward.
I would like to see Blizzard come up with a new Intellectual Property. Their three universes all date from the 1990s. Perhaps Titan would have been a new IP, but that's been sent back to the drawing board.