OK, so we know that this DLC will add a new storyline, new characters, new enemy types, new weapons ( eg. crossbows), new locations hopefully and much more. So far, pretty standard stuff as far as DLCs are concerned and I'm guessing these are the highlights.

However, will there be more? Features that improve or change the original game? Obviously the new armor, weapons, abilties will carry over once the DLC is completed but what about features that are completely unrelated to the DLC storyline? Will they remain unaffacted or will there be some slight changes here and there?

If you're still unsure about what I'm raving on about, think in the lines of mounted combat (already included I know, and although I'm not a big fan I find that it's a very, very nice touch), barbers, crossbows (Again, I used it as an example), new skill trees, new perks (that are not related to the questline), new shouts, new warpaints... You know, small touches that expand on the original game rather than pander to the needs of vampires???

It will be intergrated into the Skyrim experience, at least that is how it appears in the trailer because it shows Dragonsreach as well as cities like Markarth on a map so.....

The other thing I would like is a Jack Sparrow beard for my character.... a small request I know

Yes, in that regard, I'm rather sure... I meant things that are not related to the DLC questline...

From what it seems like it will be integrated into the main Skyrim world. Multiple Skyrim locations were featured in the new trailer. I have a feeling that the next expansion may have more of an isolated feel to them like Shivering Isles for Oblivion.