I wouldn't be so sure that they will back down on the €10 tax, other governments including the UK have not backed away from it and the Irish government will be bouyed by this fact.
The Belgian government back down before their tax was due to be introduced and the Dutch government are considering scrapping their tax. Ryanair are bullying the Irish government into abolishing the tax, and while I'm not for bully boy tactics, as a customer I like the possiblity of this tax getting scrapped.