Jack and Copenhagen, I'd say you're comments are an accurate description of what's said by airline officials' when they're asked to operate to Cork. Why cannibalise our existing services to Shannon in particular and Dublin to a lesser extent?
However a Cork service would also almost certainly draw traffic from their competitors at other airports.
By the way Copenhagen, Aer Arann do not appear to be basing an extra aircraft at Cork next Summer. The Edinburgh route is being operated as a W. The spin in some newspapers has Bristol going Double Daily and Manchester going to 3 Daily but a closer analysis of the timetable points to the extra flights operating only a few days a week.
Once again Cork are confidently predicting growth for 2014. Time will tell although the 8% decline in November doesn't augur well for the rest of the Winter.