I'm sure that a expansion is been thought of for Skyrim but before you come up with something to sell us.
may I offer something before your company settles something in concrete.
the world of TES is large with many offerings if that was not enough you have the mini worlds of the Daedric to show.
with all of this that you can take the expansion that I'm sure is coming.
I ask that you do one thing first put to vote though the Steam and Xbox live and what ever Sony uses.
give them some of the Ideals that been cooking up not every thing just where the new expansion well go.

something like

Hammerfell the rock summerset lsle valenwood elsweyr black marsh morrowind vverderfell

or
Azura, Boethiah, Clavicus Vile, Hermaeus Mora, Hircine, Malacath, Mehrunes Dagon, Mephala, Meridia, Molag Bal, Namira, Nocturnal, Peryite, Sanguine, Sheogorath, and Vaermina

Akatosh Dibella Julianos Kynareth Mara Stendarr Zenithar

I'm sure that you pick only the ones that already working Ideals on.
the reason I bring this up is I have noticed since fallout New Vegas the developers are looking at the mods that people are making for the game and using the ideals in to the next game. This is great wonderful in fact its like having free bata testers that remake the product before the next one comes up.With all that why not go out in limb here and let the players vote on where the expansion goes.

now I'm more then likely not going get chance to vote due to my job but out all of above I would like to see black marsh ever since I read the in game books in Morrowind. The whole Ideal of hidden guerrilla fighters underwater ready to spring forth kill imperial troops moving though the marsh always got my Imagination going.
Though it's more likely one of deadric realms if thats the case then I would love to see Vaernima realm. Though I think that what I in vision a nightmare world locked in place not switching every 5 min due to her near death by attack by another Deadric Lord Peryite also known as the Taskmaster Yeah having the bunch of little taskmaster agents reshaping the world of dreams to black & white world that slowly fads where ever they walk. A land scape that can be upside down in some places a chance to bring the spell Levitate though I know that some in your company feel that this spell should never be used put a drain mana as long as its in use or time limit in only the world of Vaernima.(yes that is stretching it some but I want levitate back ).

Now if the ideal is to go back to where the T.E.S. game have been like Vverderfell or something that would be great too.

So I say make vote poll with ideals you already have just to where it take place and let the people vote on it. The control that steam Xbox live and what ever Sony uses provides with a little work that only the people that have the game can vote and with all the [censored]s (sorry did not know that donkey was bad) that steal it the game will make some scramble to get a copy just to get a vote. If the company is going to waste money on live action tv commercial to get new people to play the game. Providing the one chance to take next chapter of T.E.S. will take place seams even better for all the people that played there friends copy or even stole a copy a incentive to buy it legally.

but like I wrote its just an Ideal .
To all the people that read this and feel that this good ideal please bump by putting where you would like the next expansion takes place