I think Cork is more or less breaking even if the interest on the debt isn't factored in. The 24 hour operation at Cork was introduced in the late 90's for reasons that had more to do with work practices than operational needs.
Well that's good news for sure
I definitely think for the amount of traffic using Cork between midnight and 6am its just not sustainable to remain open, even most Cargo operations compared to say 2006 are gone - If cargo level's returned during that time period I'm sure it could be then justified, although with one of proposals' at Shannon to turn it into a major European cargo hub this could be a portfolio of business that Cork will go without as a result.