Courtesy of Bungie, here are the full Destiny December 1 patch notes:
Exotic Weapons are designed to look, feel, and sound overpowered. At the same time, they are not supposed to break the balance of the game. We hope these weapons challenge the way players think about their loadouts. Exotics will be a constant work in-progress!
General In preparation for the Dark Below, Exotic Armor and Weapons no longer require Ascendant Materials to upgrade The final upgrade node of all Exotic Gear will require an Exotic Shard Exotic Shards can be obtained by one of the following means: Dismantling unwanted Exotics Purchased from Xur for 7 Strange Coins Exotics now start at a