jamie2k9 - you already answered your own question. Those long haul routes that Belfast lost the passenger numbers increased on the corresponding flights to those destinations from Dublin
The NI assembly had to ask Westminster for special dispensation on APD as they were United had already announced they were pulling New York. They received this however Newcastle will not get such help.
I have worked on this issue for sometime and I can assure you that their are some very worried folks in the NE Aviation sector
Don't agree at all as the long haul routes that Belfast lose were purely dependent of leasue travelers and only operate peak times of the year. Incomes are squeezed and family Holiday is high on the list of things to be stopped. This belief that everybody is traveling to Dublin is a load of crap as its not the case its purely down to the fact people are replacing Florida etc with Spain and Portugal. United were not charging passengers for APD in NI to remain completive to DUB and keep passengers at BFS but I believe that United would like to pull out of Belfast regardless of APD as its already a marginal route. Growth at DUB is down to EI developing their Hub and increase in passengers coming to DUB from the US and not leaving Ireland both sides or the border and if I could post detail to back it up I would but I can't.
APD dropped in NI will have zero benefit to the region as no new US carrier will launch a route form BFS to the US or Canada they will go where they can make money and have access to a wider market and can be accessed easier for everybody and that is DUB. All major cities and towns in Ireland now have 24/7 bus service and a motorway to the airprot from most areas the airport can be accessed around 3h and this is why airlines will pick DUB.
BTW Aer Lingus cut there own MCO service from DUB last year and that shows the state of the leisure market....