Interesting to note that ORK-DUB will get even more competition from the middle of next year, but it won't be another air service! Irish Rail look like they finally will be able to offer an hourly service using new locos and rolling stock. The first train sets arrived recently with the rest to arrive over the coming six months. Advantage is 2.5 hour travel time, city centre to city centre. The appalling rail service to date has benefitted Aer Arann, but many commuters currently using air will most likely make the switch back to rail.
Interestingly, price wise the rail and air option are pretty similar.