Gibney, we know about the AA service, thanks (I think maybe that's why Platinum206 referred to it as "already announced"
) - the question was specifically about United.
P206: if UA started Dublin service it would have to go via SNN or be complemented with a separate SNN service (as AA are doing) - unless the stopover falls away completely before then, which I don't think is on the cards. Could happen, but UA isn't flying transatlantic 757s for thinner destinations like SNN, and so would need to put a 767 in there. Alternatively, would a one-stop service out of DUB really be competitive with the existing/coming non-stops?