I come back after a two day break and wow, I find there actually is a TES:V game in making and it's Skyrim for that matter? How exciting indeed!

But I have a few questions.

During the Oblivion Crisis, what was happeneing in Skyrim? You barely heard anything in Oblivion regarding information to Skyrim.

Is Skyrim still spilt into Holds? Ex. Eastmarch, The Reach, Winterhold?

I believe all that is known about Skyrim you can find here:

http://www.uesp.net/wiki/Lore:Skyrim

This site seems to be pretty accurate with lore information

I think the "Civil War" has something to do with the Wolf Queen of Solitude, Potema, Aunt of the Empress Kintyra, launched a rebellion In the 120th year of the 3rd Era

The pocket guide to the empire speaks about the existance of the H?rme, an underground movement that claims Potema and her deposed son Uriel III to be that last of Tiber Septim's true blood. I believe following the the unrest in Cyrodil and its lack of a true heir to the throne, would probably cause this movement to increase in tenacity, possibly causing a civil war in Skyrim, this would explain the importance of the term "Dragonborn" as used in the trailer, possibly implying that the player is the Dragon Born, and must unite the province, which draws several cues from Morrowind and the Nerevarine. This fits in well with the lore of the elder scrolls, and fits in well with the trailer, this is just my opinion, and its subject to change, but at the current time I believe this to be the most likely story line.

The most recent info we have on Skyrim comes from the http://www.imperial-library.info/content/pocket-guide-empire-third-edition-throat-world-skyrim.

The civil war could just be two groups of Nord Clans who want to unify Skyrim because of the chaos that was caused by the Oblivion Crisis.