Aer Rianta is an Irish state company, not a dublin company if I recall. As far as I know Cork is in Ireland.
But Aer Rianta no longer exists, the DAA (Dublin Airport Authority in case you don't know) got all the assets, Cork got none and on top of that was asked to pay for the terminal the DAA built.
I also believe that Cork and Shannon got new terminals before Dublin, where they are still waiting for one.
While technically Dublin has yet to get a new terminal, it has got a number of Piers over the years, Pier D was opened just last year. The original terminal now forms only a very small part of Pier A where Aer Arann, BA Cityflyer or Cityjet flights depart from.