I think Neo's hinting about the civil war questline as if it's equally important, and thus Skyrim has no one main plot?
Though I disagree, I think the world-ending dragon thing is clearly the main quest. The civil war is a pretty big deal I guess, but not obviously apocalyptic, and it's also completely optional to even begin.
From a lore perspective, the ultimate goals of the Admeri Dominion (the major causative factor behind the civil war, aside from ulfric being a megalomaniac) are very much "End of the world" in scope.
The aldmeri dominion intends to mythically re-write the world, by removing Talos, and all instances or references to the human races on tamriel, in much the same way the Marukhati Selectives reforged the personifications of the divines when they "danced on the tower."
Considering that "the world", Mundus, the mortal plane, was created by the entity responsible for the creation of the mortal races (Lorkhan, the trickster-- Aka, Shor, and other names) men being among his most prized creations, and playing an essential role just by existing in sustaining the mythotecture of the TES universe, the goals of the Aldmeri Dominion are very much to "End the world", so they can create a new one that they like better. (Much the same kind of plan that Dagoth Ur had in Morrowind.) Hints about the long-feud between humans and elves can be picked up casually by listening to the last remaining falmer guarding the old temple complex of auri-el.
Remember, the TES universe is not as.... rigidly grounded.... on mundane principles as ours. It is based on myth and magic. The aldmeri dominion is using mythic deletion to re-shape the world.
In that respect, the civil war takes on whole new tones.
(It's why I side with the Empire in the civil war, despite the egregious acts they engage in. A unified empire is required to stop the Aldmeri Dominion's sinister ambitions. Divided, tamriel will fall. Deep down, the empire LOATHES the aldmeri dominion, and only works with them by force. Somebody needs to return to HighRock and get the giant stompy robot-- er.. Numidium.. out of the bay, and back into action bootstomping genocidal elves.)