I also think that Daenerys will be making a journey to old Valyria, and I imagine that she will uncover some secrets about the creation of Valyrian steel and dragonglass, since these lost arts have been incresingly mentioned in the series, and they will be necessary for the inevitable battle with the others. Who better to save the day then Dany with her army of unsullied all wielding valyrian steel and dragonglass?