brianh
quite happy with neighbourhood having read http://wiki.openstreetmap.org/wiki/Neighbourhood
because they were established by act of parliament with very well defined text boundaries, which I used to add them to OSM, I would be reluctant for the historic-township tag value to disappear but am unsure if the tag place can be used twice each with different value. Others outside the present city include Blackrock, Dun Laoghaire (previously Kingstown), Dalkey and Killiney.

Hope this helps.