This Tinfoil Hat post is not meant to be taken as established lore, but merely as an exploration of what that lore could mean.
Sometimes an idea starts small. I was musing about Saronite, the literal blood of an Old God, which as we all know was used as the material that created Icecrown Citadel. Then I thought about how the last dying breath of an Old God became the Sha, actual embodiments of corruption.... and how, even after the death of that Old God, the Heart of Y'Shaarj could taint the entire Vale of Eternal Blossoms. The very substance of an Old God... its blood, its flesh, even its last breath can taint, warp and corrupt the world.
Then I started thinking about the madness the Old Gods engender. Upon first arriving in the Howling Fjord, members of the Explorer's League were driven mad by the thoughts of Yogg-Saron, trapped within the Whisper Gulch. Yogg-Saron, after all, was massive - his tendrils extend all the way across the continent, from Icecown through the Storm Peaks and down into the Dragonblight, the Grizzly Hills, into the Fjord itself. And this got me thinking something else.
Northrend is dominated by Yogg-Saron... but the Old Gods predate the Sundering, and so when all continents were part of the great original Kalimdor, that means that the Old Gods lay submerged beneath it as well. The Old God N'Zoth most likely lay beneath the center of the primordial landmass, ancient C'thun lay to its west, and before its death at the hands of Master Ra and the Mogu the south was the domain of Y'Shaarj whose seven heads consumed hope and begat despair. But many were the Old Gods, and powerful (or so the Klaxxi maintain) and this leaves me to ask - was there a god to the East? And what became of it?