meh i say let them keep their titles, its all history now, they have no real say in what goes on its simply put, celeb status and little else.
the history is pretty interesting though, I live in a town with a castle that dates back to the 13th century (Henry VII), its interesting to learn how the times were in them days, most of the whole royalty thing is not much more than the succession of tribal leaders stepping up and continuing the tradition with family members taking up the places of their dead parents. and so on.. in this day and age, they have no real purpose or job so to speak, but i don't think dethroning ppl for the sake of it really makes any difference, what would we actually gain from that?. also i think ppl are entitled to their heritage without it being the business of anyone else.