The way I understand DLC is working is that there is going to be two large pieces of content and very little small DLC (like in Fallout) This could mean two Knights of the Nine sized releases in addition to an expansion (like Oblivion) or two full expansions (like in Morrowind). My guess, or hope, is that we are going to get two full expansions. These are my speculations/ideas if those DLCs turn out to be full expansions.

What I dont think it will be about: Although the Thalmor and Aldermi Dominion have had a large presence in Skyrim, I don't think anything will come of that for TES:V and will more than likely be saved for the next game. I also don't think it will include simply added extra content to the current gamespace, as all previous expansions have been set in new lands. Lastly I don't think it will occur in a Daedric realm again, since the focus on Daedra in Skyrim is severley reduced.

What I do think: Previous expansions have all been about content relatively unrelated to the main game, save for Tribunal, but only kind of. They also don't seem to focus on catastrophic threats like the main games do. From these and in-game speculations, these are the ideas I have.

-Retaking Orsinium - Only recently have the Orc strongholds appeared in Skyrim and only because Orsinium was sacked by Hammerfel and High Rock forces. This expansion could focus retaking Orsinium for the orcs and allowing the mountains of Orsinium to be a new gamespace. The orc strongholds do not serve much purpose currently, with only a few minor quests and very few traders. The very presence of these strongholds is kind of odd anyways, since there was no lore of this prior to the game (at least that I know of).

-Learning About the Dwemer - Skyrim is one of only three provinces to have Dwemer ruins, the othere two being Hammerfell and Morrowind which have both already been featured in games. Since this is likely the last time Dwemer will be featured in a TES game, it would be a good time to finally explain what happened to them and perhaps meet them? The path going into Morrowind is also interesting. I don't think there have been passes like this is previous games.

I really enjoy your ideas, I do believe one of the DLC’s will cover the Thalmor. They’re presence in the game is undeniable as they LOVE to tell you over and over again when they see you. Something along the lines of fighting the Thalmor out o Skyrim is what I’m thinking.

Another idea I’ve had is a Dunmer uprising, you find a book in the game which tells you that the Dunmer are planning a rebellion of they’re own. As far as I know it’s a very hard book to find, I found it between to rocks in the mountains. After reading it I instantly thought DLC, it talks about them wanting to take over Windhelm first. Allowing them to spread out through the continent, I see these two ideas happening before anything with Orcs. I still enjoy your ideas tho.

Knights of the Nine was a bit of a weak expansion, IMO. What we should expect are expansions similar in scale to Morrowind's Blood Moon expansion, as well as the Tribunal. Those are what I call true expansions, not some dinky little DLC.

An expansion is intended to extend a game's lifetime by adding a new world or chunk of it, and a whole game's worth of content to a pre-existing game. It's actually a very low-cost way to make a completely new game, as opposed to wasting three years of dev time on a sequel.

I like the idea of retaking Orsinium for Tamriel's true superior race. The Orcs.

Knights of the Nine was basically a quest line and thats it. It was a DLC in every sense.

Todd said there would be two or three expansions, I hope they do them like Bloodmoon and the Shivering Isles. Now that would be awesome.

I doubt we'll go back to Morrowind (particularly Vvardenfell) but today I was talking to Vilkas and he made a remark like: "I think I've killed one of every creature in Skyrim by now. Maybe I should go to Morrowind now! Haha!"

Probably just Bethesda teasing us.

Considering the Vvanderfell landmass IS coded into the game, I hope we can return there for an expansion

Getting to see some more dwemer stuff could also be interesting, though.

EDIT: Also an expansion that adds dropbears to the game, though that probably isn't happening