Rules wise, there isn't any reason it shouldn't do anything other than what the spell does (i.e. make it so the user can then touch attack someone to deliver the shocking grasp).
Opinion wise, it would be a better visual to have the electricity come from the wand.. but, again, back to rules wise, it keeps more continuity if it simply leaps a spark to the user's hand or something and therefore allows the user to do a touch attack as if per spell itself.