There will never be Irish Postcodes, the really simple reason for this is that we don't need them. Locations in Ireland always record their county, town/city/village and road. If you think practically, everything is still going to be sent to the nearest towns sorting office, where one post-person walks around the corner and another drives ten miles.
The infrastructural investment required for such a system would be prohibitive until either more people post, or, the postal system is privatised and the need for two post-people for one job instead of using technology actually is finally acknowledged as illogical. In saying that I did march today!
By the way I used IED6W (Ireland then postal area), I think this may happen al right, places may be divided into 20 or 30 different areas, each with an office, not determined by popular. We'll probably never (unless people start multiplying, privatisation or a lack of postal workers in the future) have a totally automated system.
Bad news for you - the postal system will be privatised/liberalised by the end of next year and not everything will be handled by An Post anymore in their sorting offices - in the same way as couriers do it already! Also bad news -there are already post codes in use!!!
Bad luck - your D6W tag is no good to the new entrants who will be delivering your mail from next year onwards. For your info 40% of the Irish population lives in rural areas with ambiguous addresses and these are the majority that will dictate the introduction of Post Codes - I'm afraid you are in the minority in D6W - or is it really D12 ????