Every specialization will be receiving an additional Artifact appearance in Patch 7.2. Guardian Druids will receive an epic new bear form. The new appearances are tied to proving class trials and it was mentioned during the panel that you need to stand out if you have to obtain the appearance.
At the end of the day, the appearance should also be a visual indicator of your skill, let's say you join a dungeon group and you have this great new Guardian appearance, chances are most players will recognize your skill based on the appearance.
The Artifacts have been in the game since alpha, but with no source indications.

Druids are getting a spectral cat form.

Guardian Druids are obviously the winners by a large margin when it comes to 7.2 and appearances.






Warriors are getting flails!