Momo,
I agree, although Aer Lingus had a very heavy presence and involvement from day 1 of selection last year (from what I seen). With Aer Lingus staff available for questions, and they sat in on the interview. I assume this was probably to learn and get a feel for how it is ran efficiently, and now its back to Aer Lingus to choose their own.
What is noticeable, is that they have set out the dates for interview, which is only 5 days! They're giving themselves plenty of time from application close to the first assessment centre (near enough 2 months). At that, considering the assessment centre is only 5 days this time as opposed to 10 last year; you're looking about 80 candidates at this stage (opposed to the 160 last year). Its going to be a toughie to get through to; likely going to be on the merit of CV and online test scores.