Czech Airlines
Air Baltic RIX-DUB-JFK-DUB-RIX
Oman Air
Cyprus Airways LCA-DUB-YYZ-DUB-LCA
Air India Everywhere in India-DUB-The states
Singapore Airlines
Aeroflot
Manx2.com
Virgin Atlantic
Arik
Looking at this list, I think the most realistic are the Oman Air, Air Baltic and Cyprus Airways links.
Oman Air operate A330's on all high volume and long-haul routes and if they were interested in starting up US routes like the rest of their Gulf neighbours, these would probably not be deemed long range enough without a stopover somewhere like Dublin.
Air Baltic, well due to the amount of their nationals in Ireland and that they are likely to want to serve JFK with their 757-200's, again a stop is needed and they can pick up some extra PAX.
Cyprus Airways, a similar reason with trying to serve Toronto with a A330 from Larnaca, though should have the range with a plane like that. Not sure there's too much demand between Canada and Cyprus (especially if they don't serve anywhere in the US), but I could be wrong.
Can't see the rest happening, though maybe Aeroflot using Dublin as an A330 stopover for the likes of Havana or Los Angeles could still be runners, especially as they used to use Shannon as a stopover.
Air India though......the cancelled flights on the live departures at Dublin Airport are encouraging but Aer Lingus did once load Cairo and Bangkok into their system and nothing came of either.