Well I'm still waiting for Citywing's Dublin to Derry flights to become bookable. Citywing successfully applied for funding but I haven't heard anything since.
Hopefully the above doesn't have an effect (unless it's a positive one!)
*edit* I just asked Derry Airport on Twitter about this, and mentioned Ryanair opening a base at Belfast. This was their reply:
@ker_fuffle @Fly_Citywing It is hoped Derry to Dublin service will commence in April 2016. Will keep you updated. #FlyLocal #ChooseCoDA