Ok, now I know that some argue that the Old Gods that we have faced and *killed* up to this point (Yogg-saron, C'thun, soon-to-be Y'shaarj) were never really killed; some argue we only killed their avatars or what little of their power seeped to the surface of Azeroth. If we consider, however, the other possibility that we have indeed been killing off Old Gods left and right (which it seems pretty undeniable that Y'shaarj will be killed, all thats left of him is his beating heart which is linked to Garrosh), then what repercussions will the denizens of Azeroth face? The Titans imprisoned the Old Gods beneath Azeroth rather than kill them outright (except for Y'shaarj, which raises more good questions) because the death of the Old Gods meant the death of the *cursed* inhabitants of the planet. If we eventually are forced to kill off all of the remaining Old Gods, will we essentially doom ourselves? Does their *curse of flesh* that binds us to life weaken with each consecutive death of an Old God?
A crazy theory that I've been harboring is that in a future expansion, the final Old God will wholly and totally break free from his prison (N'zoth perhaps?), the Titans will return to Azeroth in person, see the devastation that Algalon saw, and decide to purge Azeroth--starting with killing the final Old God. As the denizens of doomed Azeroth, we will have no choice but to ally with the final Old God and fight back the Titans. I find some plausibility in this because Blizzard has hinted very heavily in Mists (via the Mogu and their lore) that the Titans weren't exactly the perfectly upstanding, righteous deities that we believed them to be; they have a darker side.
So what do you guys think?