In all honesty, I think the Irish are just beginning to feel like they can admit that they don't want a religion.
I spent several weeks there in 2004, before this official "drop." Met hundreds and hundreds of Irish Catholics, not a one of which gave two hoots about Catholicism, church, or "god." They were atheists, but called themselves Catholics. A "culture" thing.
Hie to Kolub, we had a very similar experience when visiting my Irish Catholic relatives in rural Co Galway, people are culturally Catholic but are very fed up with the pedophile scandal, the Magdalen Laundries scandal, and the whole culture of clericalism. My husband is a Jewish Atheist and was delighted to meet several people who casually said they were atheists, no big deal and not a "terrible" admission like it would be in the US.I went to Mass at the old church my ancestors attended, and found the priest very liberal, not like some of the old hard-core Irish-American priests at home.
Just like here, the young people are not much interested in religion and while the policies on abortion are bad, you can get the morning after pill in the local drug store without a prescription! Ireland is much more complex than the stereotype many have of it.
Looks like Ireland is starting to go the way of the rest of Europe. I notice that immigration has contributed to some religious diversity there (Islam, Orthodoxy, etc.)