Skyrim is now live on Xbox 360, with the PS3 patch expected to drop later today. Apart from numerous bug fixes, the update's hallmark features are the new Legendary difficulty setting and Legendary Skill system. In the new system, once a skill reaches level 100, it can be rolled back to level 15. As Bethesda points out in the patch notes, this technically removes the level cap from Skyrim.
The patch went live on PC last month.