Didn't we have this rumour a few weeks back and the response was "until we see them in the flesh (so to speak), let's not say anymore"?
It would not surprise me, that said. Boeing is clearly aware of the potential for Aer Lingus to grow on t/a routes and wants to be the provider of its aircraft to facilitate this growth (including 777s). The A330-300s have served it well, but aren't really good for much more than west coast flights.
The wet lease aspect won't please IALPA, unless these crews are part of the training team.