Just after reading that Bus Eireann and Translink have introduced an extra 10 daily services between Belfast and Dublin from 2 June to 21 September. 7 of the extra 10 daily are non stop services between Dublin Airport and Belfast and take just 1h50m. Now there is an hourly airport services 24/7+ the 7 daily non stop services that operate. Won't help Belfast and NI stop the traffic bleed to DUB.
http://buseireann.ie/pdf/1367495210-001X.pdf