Government subsidies for NI are being cut in line with the rest of the country. There is a general agreement that there should be a somewhat more level playing field in terms of taxation across the island of Ireland as a whole. Remember that the UK government have handed the Republic a huge loan over and above what it(ROI) received from Europe. They promptly reduced their APD and that has disadvantaged three UK airports.
The NI government recognises that inward investment depends ,to a degree,upon good airlinks to the rest of the world and it is with that in mind that this issue was raised with George Osborne on his last visit here.
If there IS any movement centrally I suspect that it will be a case of robbing Peter to pay Paul.
That however is what the politico's are tasked with doing.
I shan't hold my breath.