...During the DB quest line, Who becomes emperor? Tamriel has no leader, and skyrim has no king, yet everything seems normal. And if the king of skyrim has been dead for months before the return of Alduin, what happened to the moot?

I think they will make a DLC or something that should change something.
But its hard cause Skyrim is Skyrim.

I've posted this a few times, but here it goes again..

I think that some major event that will overshadow all of these choices the player is left with will be happening soon. There are so many choices that they player has that have potentially vastly different outcomes. I think that something crazy is about to happen that will make all of those choices (such as whether or not to kill the Emperor and which side the player chooses in the Civil War) basically null and void.

After Oblivion was all said and done, and the end results there left Tamriel within an Emperor or any potential heirs, Bethesda published two books that take place after the Oblivion Crisis, and that pretty much ties up all loose ends or answers any questions of uncertainty after the fact.

Yep.

Oh, the "lost tomes" to which I often refer.

Are you talking about the books about the floating island? Those actually explain things after the Oblivion Crisis? hmm.. I'm gonna have to read those if so..

Well, there are two theories as to how Mede died. Some say an assassin, but there are rumors too that he died of natural causes on the way home from Skyrim aboard the Katariah. That is probably how Beth will handle Mede.

I wonder if the Elder Council is still around? What about Ocato?

Ocato got killed by a Thalmor hitman, and the Elder Council is still around. After all the man who did the black Sacarament to kill Titus is in the Council.

Indeeeeeeeed. Also they're pretty rad and it also explains why Umbra, the most broken sword in TES, is not in Skyrim.
The Elder Council is indeed still around. Amaund Motierre, the man who hires you to assassinate the Emperor, gives you an amulet specifically made for members of the Elder Council as payment. As for Ocato, he realized the threat of the Thalmor much sooner than most people in Cyrodil or even Tamriel. So he much greater knowledge as to how to counter them and what their plans may be, so naturally the Thalmor had him assassinated. His assassination lead the remaining members of the Council to start conniving and backstabbing and grab for power, which the Thalmor took advantage of by going off and doing whatever they wanted since the Empire was all splinted and had no leader and such.