After the return of the cape I would be delighted to see another Medieval fashion aspect taking today's trendy youth's fancy by storm: The Mi-Parti. Referring to a bi-coloured garment ('separated in the middle') the Mi-Parti first occurred in 11th century fashion. With the wedding of the German Kaiser Otto II and the Byzantine princess Theophanu, more colourful and more precious fabrics entered European costume. Originally the Mi-Parti was worn only by servants and court jesters indicating the subordinate position of the wearer.
Going by Alexis Mabille's last week's Paris Haute Couture show, I believe he'd be delighted too!