If Bethesda were to make an expansion pack for Skyrim and targeted it at characters over level 40. How would you like to see them go about it?

Would you like to see new stronger enemies?
Would you rather larger quantities of enemies?

What other game play mechanics could you think of that could be implemented into Skyrim to increase the challenged and appeal for high level characters?

I want an enemy that has the chance to one hit kill he player regardless of health or armor rating. This will make those who abused crafting actually have to pick up a little strategy.

I'd only like this, if there was equal chance to one hit the foe.

Personally I don't care if people "cheat". Its a single player game.