Last week's Economist had an excellent supplement on the ligistics of the changeover to the Euro in those states contemplating it in the New Year.
And, like so much else fogging the issue, once one looks at it clearly, it ain't such a big deal (other than Tesco's in Ireland havign to reinforce their floors to cope with the extra small change for three months!).
There's an index of the Economist's coverage of the Euro here - and so far I've seen little to make me rreject the idea of joining and much to commend it.