Luckily, it seems, that nobody really knows what will happen apart from the heralds of Armageddon, of course.
For the countries of the E.U. it is different and markets are inevitably going to fluctuate.
I will be moving to Poland in the near future.
Poland will not be joining in the near future, every year they say they will join in two years, this time to add a bit of spice they have said four years:
On Friday, 11 December Polish Prime Minister Donald Tusk said Poland could join the eurozone in 2015
en.wikipedia.org/wiki/Poland_and_the_euro
What does that mean? well the zloty is not as stable as the Euro, so fluctuations hit independent currencies more, so if the Euro does drop a little, the Zloty drops a lot because it is considered more of a risky currency than the Euro.
But inevitably Poland will join the YoYo
Under the terms of the Treaty of Accession 2003, all new Member States "shall participate in the Economic and Monetary Union from the date of Accession as a Member State with a derogation",
When it comes there'll probably be a price hike, like there was in Ireland and Slovakia.