For Shadow, Void Torrent (our Artifact spell) and Mass Hysteria (one of the golden traits) are absolutely vital to how the spec plays. Remove one of them, and the spec no longer works. For a lot of specs, losing their artifact traits next expansion, would require a full design to make them playable again.I can see Blizzard making the artifact spell baseline for each spec, and then the 3 major artifact traits would become talents, that would make a lot of sense.