Ryanair
Many people find taking the train less stressful. Maybe if Ryanair could be more flexible with Domestic services they might get more train users to switch. The emphasis on checking in 2 hrs before departure is a huge turn off. Maybe allowing people to change flights without incurring massive extra charges might also help.
Aer Arann might be still on the route but Ryanair have very very big cash reserves so I'd expect them to stay and the evening departures from Dublin and Cork should generate new business during the summer months.
CAA must be hoping that both carriers stay on the route as if either pulls out it will almost certainly lead to substantial negative growth at Cork for 2007 in view of their failure to attract any significant new business.