MarkD
That wasn't quite what I meant. I was assuming the Shannon stopover was gone and Aer Lingus' main aim would be to be the first onto a number of routes. It was a way around the lack of suitable planes.
I can't really see that it's possible to run an A319 transatlantic profitably. However, it should be able to make the run to some north-eastern./northern cities - Philadelphia, Detroit, Minneapolis(?) - to establish routes while suitable aircraft are sourced.
After that perhaps they could be used to provide more suitable capacity out of Shannon, but as I said, I have my doubts about whether you could operate an A319 profitably on transatlantic routes.