Says ArenaNet, "Currently, it can be a little overwhelming to try to sort through it all and customize your character exactly how you'd like to. Our answer to that is the Wardrobe, which makes it easy for players to change their look at any time and to share cosmetic items across all the characters on [their] account." In other words, a skin unlock for one character will work for alts too, and players will use transmutation charges to swap their looks as part of the new simplified transmutation system.
ANet launched a brand new dev blog, video, and gallery today to toast the new feature. Enjoy!