I don't know too much about Wizzair, but I wonder where they're considering. Their bases seem to be Warsaw, Gdansk, Katowice and Budapest.
Two of those four already have services from Cork. Are they the type of airline who'd be put off going head to head with an established carrier?
I'd say Katowice is most likely. It's in quite a densely populated region, there are no services from existing carriers and it could attract a certain amount of outbound from Cork because of its proximity to Krakow.