Having passed without the need for a vote in the Dàil on 1 July and by a vote of 48-4 in the Seanad one week later, the Irish civil partnership bill only needs to be signed by the Uachtarán to become a law.
PinkNews: Irish parliament approves civil partnerships bill
PinkNews: Ireland’s upper house passes civil partnerships bill
Given what Wikipedia says about Mary McAleese and GLBT, it seems improbable she wouldn’t. Which would mean another huge step forward in a country stereotyped as Catholic and thence homophobic, even though Ireland wouldn’t have gone as far as Spain and Portugal, which legalized same-sex marriages.
UPDATED: Mary McAleese did sign the bill into law. Marriages may start from January.