I don't know if it will come to Cork, but with three more to come, the odds of one of them turning up must be decent. That said, it might be primarily used to reinstate a 2nd rotation to Birmingham and Manchester and to operate the Cardiff route, which currently uses a Dublin-based aircraft. I guess that would probably leave open the option of 1 more rotation a day, but where? It would have to be near enough to get there in an ATR, but big enough to sustain a service and presumably also somewhere currently unserved from Cork - Southampton, Leeds/Bradford, Nantes maybe.
I don't think Aer Lingus have any A320s arriving before April 2011. I still don't know what happened to the two that left Gatwick. Possibly the opportunity was used to return some to the lease companies.