I have my medical in a couple of weeks. When I rang I asked that very question. Apparently, it is not officially a JAR medical, as Ireland has yet to fully introduce JAR-FCL. However it is exactly the same medical as you would undergo in any other JAR country and if you ask they IAA they can give you a letter stating is JAR compliancy.
I noticed when I was looking at the application form for BAE Systems, they reguest a Class 1 from either the UK or Denmark! Aer Lingus currently send their cadets to BAE, and I sure everyone of them did their medical's in Dublin!!!
As the previous post says, call Adrienne if you have any questions or doubts. Let us know how you get on.