What are Dwemer doing in Skyrim?....unless Skyrims boarders now pour into Mainland Morrowind, last I check Dwemer cities were in morrowind >_>
Dwemer ruins can be anywhere they want. The future borders of other civilizations wouldn't affect where they built their fortresses. It could well be that the Dwemer built extensively into Skyrim past the Velothi Mountains, we'll just have to see.
Their affect on the world still standing today, I think.
There were Dwemer ruins and inventions in Morrowind, and they didn't play a big role. What's the big deal?
The Ayleid's didn't play a massive role in Oblivion.
EDIT: Lady N, you beat me.
I have to disagree, the Dwemer were at the center of or heavily involved the story for both Morrowind and Tribunal. True the Ayleid's didn't seem to have much of a role int he mainquest, but I think that just be the virtue that they are bringing the Dwemer into Skyrim, there has to be something interesting going on. Not sure if I'd be willing to bet it has to do with the mainquest, but it could be.