There will also be a brand new item type, a series of "legendary item advancement scrolls". They will provide an alternative method of improving or altering legendary weapons, and will be found both as loot from enemies and from the deconstruction process. In addition, crafters are getting a significant nod with the introduction of a fourth relic slot that can only be filled by player-crafted relics. It gets better: every crafting profession can make a different kind of relic, providing a range of improvement options, and ensuring that no crafter is left out of the fun.
To read up on all the details of the upcoming legendary item changes (including specifics on how experience will be altered) see the full dev diary at the official site.