Now is it a slot swap with Aer Lingus taking the earliest A321NEOs in 2016 and renegotiating A350 deliveries for later in the decade or is it Aer Lingus cancelling the A350 altogether in favour of the A321NEO?
The latter would be a poor choice in my opinion, yes the A350 is considered quite large for Aer Lingus and this has even been stated by the CEO but it currently seems like the only viable replacement for the A330s which will need replacing whether they like it or not.
The A321NEO for Aer Lingus would be no surprise though, I'd be more surprised if it wasn't ordered eventually! It would give the long haul operation from SNN a secure future while potentially make ORK-East Coast flights very possible and naturally complementing the A330/350 based at DUB. The NEO family is an ideal replacement for the bulk of the short haul fleet anyway, I just imagined the A321NEO being part of that order with a few designated for transatlantic ops rather than being ordered in favour of the A350. It'll be interesting to see if any more details emerge from this rumour.