The new system, which Cryptic is referring to as "refining" rather than "fusing," enables item enchantments to gain refinement points as you play; once an enchantment has enough refinement points, you can use reagents to rank the enhancement up to the next level. Additionally, unslotting enchantments and runestones now costs gold instead of astral diamonds.
Refinement stones, which are effectively large bundles of refinement points, have also been added. They'll drop from skill nodes and bosses, albeit rarely. The changes are live on the Neverwinter test server -- Cryptic is asking all players to check them out and offer feedback before they deploy.