Story:
Skyrim is being attacked by an unusal amount of Dragons coming from the same area and you are sent to investigate. You find out that Dragons fly down from the same exact spot every morning and fly up every night at that spot. You have to manage to tame your own Dragon and find where the Dragons are originating from. You discover a floating continent above the clouds. You have to make your way through the new area fighting Dragons and other new creatures. On the far end of the continent,there is a castle occupied by a Dragon God, who you will have to kill to complete your Quest. Also some side-quests will be possible,like Shivering Isles.
What do you think about this? It might need some things here and there. Just an thought...