User blog comment:Legend 721/Dwemer Return/@comment-4990165-20120726150018

The likelyhood of this ever happening is nil. In Morrowind it is explained the Dwemer disappered en masse when their ruler, Kargrenac. He thought himself above his mortal station and attempted to use the tools, Keening, Sunder and Wraithguard to create the Numidium. He failed, epically so and his spell wiped out the entire Dwemer populace, save one -- Yagrum Bagarn who was on "vacation" in another realm, thus he was spared the fate of his people.

If you go inside the Dwemer ruins in TES III, under all the beds are piles of ash. It's safe to assume that would be the Dwemer. They are dead, likely to never return.