I know I used this recently, but it's just so damn good.
It's come to light recently that in a pre-Mists of Pandaria event that Theramore, in Dustwallow Marsh, will be destroyed in a Horde attack. This is meant to ignite the preexisting Alliance/Horde tensions to launch us into the story for MoP. To be clear, it hasn't been clarified/indicated if the Alliance will be losing Dustwallow Marsh as a question area or if Theramore will just be rubbled. Regardless, many people are crying out over this, claiming the Alliance lost enough in the transition into Cataclysm and calling for similar Horde losses. If it's done, though, then where?
It wouldn't suffice to just say that I have ideas.
Grom'Gol Base Camp
Grom'Gol has stood conveniently in the middle of Stranglethorn Vale for too long. It's given the Horde a convenient hold into the zone that the Alliance cannot rival. It needs to burn. Like Theramore, it doesn't need to go away, but it needs to go down.
Crossroads, the jewel of the northern Barrens, has stood undisturbed for too long. Seated in the middle of Horde territory (literally), striking it down would send a message to the Horde that they are safe nowhere. Crossroads was a frequent target of Alliance raiding parties before duty called us into space. I had a former roommate who would frequently lead assaults on it, while blasting Eric Clapton's song of the same name.
The Forsaken are making ground in the northern Eastern Kingdoms. Where will the Alliance meet them in battle? The Alliance should retake Hammerfall and make it their major base in the fight against the aggressing Forsaken. The Gilneans could retake the area as a first step towards reclaiming Gilneas.
Perhaps even a unified group of survivors from Theramore, Gilneans, men of Arathor, and the Lordaeronians displaced by the Scourge and Forsaken could pull together a force dedicated to retaking the northern Eastern Kingdoms.
Metagaming for a moment, this would be a wonderful moment for Blizzard to revamp Arathi Highlands, which they didn't get to do in Cataclysm. A Forsaken base on the west and a Gilnean base in the east would make for some compelling war story.
There are, of course, several places where the Alliance could make their attack, choosing the right one will be the key. I actually really like the idea that with each expansion, Blizzard could redraw the lines and advance the Alliance/Horde war on several fronts. Or, as Blizzard is so fond of saying, putting the 'war' back in Warcraft.