Forsworn, You can either help then retake the Reach or destroy them. If you side with them you can learn some weird magic and stuff and gain them as followers. I have no idea what you would get for destroying them. They can also include more armor and weapon types. --- http://www.gamefaqs.com/boards/615803-the-elder-scrolls-v-skyrim/62287165 - restored faith in humanity. 3/13/2013, shipment date
I'd rather they save the Thalmor for the next game, since I don't think it's something one little DLC should cover. I'd most like to see another daedric prince and I'm thinking Boethia. This would be the best way to bring back the thing I missed most from Oblivion. The Arena.