Are you tired of dealing with dual specs in World of Warcraft? It was revealed at BlizzCon that the existing spec system was going to change so that players could freely switch between specs, a feature that has been added in the most recent build of the Legion testing. As it stands, switching specs costs 100g a round, with a free swap back to your primary specialization. The developers have stressed that this cost is a placeholder, with ongoing discussion about whether or not there should even be a cost.
Being unable to freely switch between two specs would break up the gameplay for several players, but another change coming in the expansion might break up appearances more thoroughly. Armor types will no longer change for Warriors, Paladins, Shaman, and Hunter players at level 40; all of those classes will use the appropriate armor from level 1, which means that several old Mail pieces are being upgraded to Plate. That means that existing transmogs for Shaman and Hunter may well become unwearable and unusable, something worth considering as you determine your character looks going into the expansion.