Just wanted to throw something out there....
The Shivering Isles DLC for Oblivion was fantastic because you had to play both the Dementia and Mania quest lines to get all the xbox achievments.
It added a lot of replay value to the game and it was good to see both outcomes and how preceding choices affected them.
Will something similar happen for Skyrim? I know it's a long way down the line for Bethesda to be thinking about this but I hope it happens.

Please use the existing Skyrim DLC discussion topic (link below in my signature).