Hi Mark,
I'm not on 3 Ireland but I can tell you that no operator in Ireland offer the
N95 as one of their handsets, be it pay as you go or contract. I don't know if they will in the future as it's something I have not looked into. Even on Nokia's IE website they list the
N95 as "Coming Soon" even though you can buy it SIM free from various retailers.
I'm on Vodafone and will be buying my
N95 directly from Expansys SIM free. I saw in the UK that Vodafone and Orange have disabled the VoIP functionality on their
N95 phones and I'm sure so will Vodafone in Ireland if they do eventually sell it. Ok, it's just one feature and everyone may not use it but screw them if they think I'll wait for them to bring out a phone that they've tampered with to protect their revenue.
Of course a SIM free
N95 will work with your 3 SIM. The only problem after that is the €740 price tag!