#0 - Oct. 13, 2010, 3:01 p.m.
Blizzard Post
Originally a magic brought to the citizens of Azeroth by the Highborne, reforging will provide a new means for players to customize their gear in World of Warcraft: Cataclysm. NPCs offering reforging services will be located in all major cities, ready to assist in customizing items by altering the stats they provide. Players can use reforging to modify an item's stat values, or to undo any previous changes and allow different customization choices.

http://www.wow-europe.com/cataclysm/features/reforging.html