When clicking to equip something into the offhand slot, one-handed weapons are displayed along with shields already so dual wield is probably an intended feature in the future. It is just that the current one-handed weapon users are all very unlikely choices to give a sudden dual wield trait considering their nature. Those who have completed the leather worker storyline probably have seen the lalafell dual wielding a wand and head knife though so who knows. I figure it would come with the assassin class more then likely.