SASless is right, if it's not for hire you don't need an operators licence. You wouldn't need a Taxi licence for your own limo, right? (Well Micheal O'Leary does, but that's a different story)
If you want to stop people flying there private choppers on an N-Reg with FAA licences in Ireland, do you also want to stop the US Airlines from flying their Jet's into Ireland if the Pilot doesn't hold a JAA licence and the bird is on an N-Reg??
Might sound stupid, but at the end it's the same story, a FAA pilot flying an N-Reg in a foreign country.....
However, i do think the IAA should have the right to question the pilots and owners/operators of these aircraft whenever they want. I hope the new rules will help to make flying in Ireland a little bit saver.