I'm only on my first playthrough of the game. So far I've been betrayed by Mercer Frey, joined the College of Winterhold and become a werewolf. I just found the elder scroll in the main quest.

I do, however, know that either Ulfiric will become high king of the Empire will remain in Skyrim, the Emperor gets assassinated (though I won't be the one doing it, #empireforlife), Alduin is killed and if you did Dawnguard you can destroy the sun. (damn you untagged spoilers!)

My idea is that regardless of who wins a Second Great War is initiated and the Thalmor win and control Tamriel. As for the sun, maybe imply that either the vampires were stopped or the sun was brought back, but not elaborate on which one happened.

That's all I've got. If you have anything else feel free to post.

Here's an idea, http://www.gamesas.com/topic/1486861-official-beyond-skyrim-tes-vi-32/

Please use the above linked thread.