I'll share my experience so far in case it is helpful to anyone. I applied to Royal, Limerick, Cork and Dublin.
I have so far only heard back from Royal. I received a rejection letter late last week.
In an email on March 29th, Finbar informed me that Limerick's interview offers were being sent at that time via email. The interviews were supposed to take place in mid-April. If you get an interview, you will be notified at least 3 weeks prior. I expect to receive a rejection letter from Limerick some time soon.
According to an email I received on Nov 29/10, Cork and Dublin usually finalize their first rounds of offers in late Mar or early Apr. At that time they may accept, deny or wait-list the applicant. I hope to hear from these two schools by the end of the month.
A colleague of mine already received an offer from Cork and Royal but hasn't heard from Dublin and Limerick yet.