User blog comment:Jimeee/Skyrim 1.9 beta update adds Legendary difficulty and raises level cap (Updated Apr 8th)/@comment-86.156.211.236-20130306113612/@comment-82.31.1.144-20130307165802

Also it has an actual measurable gameplay benefit. In COD 'prestige' is literally just that, a badge next to your name saying you spent more time playing the game than others did.