The new 1.9 beta patch for Skyrim adds an odd, and interesting new feature called Legendary Skills. The simple gist of it is that the new feature allows players who've maxed out their skills at 100 and reset it back to 15, and thus allow their characters to earn even more options for perks and levels.
All the perks invested in that skill were returned just as if they had been reset with the Book of Waking Dreams. If you level up with it, the skill you're proficient in will have an imperial dragon symbol just below it. You can level it up as many times as you like and keep accumulating levels.
Keep in mind that you'll get your perk points back as soon as you make the skill Legendary, and do the whole thing again.
In theory, you'll be able to earn more perk points and a larger pool of health, magicka and stamina through the system without having to spend much time grinding on skills you don't care to use. So if you're playing a thief character and see little reason to want to level up your Heavy Armor skill, you won't have to.
The patch also sees the addition of a new Legendary difficulty setting which makes the game a lot harder than it already is, so you'll need a beefy character to tackle the challenge.
Further details on the 1.9 patch can be found here.
Picture is courtesy of SleepWithTwoEyesOpen
