Yes, it's late, but it would be strange if I didn't mention the 5 year anniversary of the Big Bang enlargement, since this is supposed to be a blog about Europe...
I remember the enlargement taking place, or at least the ceremony, which I watched live: Prime Ministers being received by the President and Taoiseach at a flag-raising ceremony in the gardens of Áras an Uachtaráin (the President's residence in Phoenix Park). The European Anthem was sung (high pitched and quite loud - possibly to obscure the lack of actual words) and a poem was composed and read out by Seamus Heaney. I was quite proud that Ireland was hosting the ceremony, and it did leave an impact on me (though obviously I was already quite an EU geek to be watching it in the first place...).
The symbolism of eastern and western Europe reuniting appealed to me: despite some of the countries arguably not being ready for accession, emotionally I felt that the enlargement was the right thing to do. And there were probably quite a few others that felt similarly.
The enlargement had a big impact on Ireland, where Poles quickly became the second largest immigrant group (after the British), and groups from other Eastern European countries found respectable places on the top ten too. As has been reflected on in the Irish Times, the immigration that came from enlargement has changed the face of small town Ireland, with Polish food shops, etc.* Now there seems that there could be some emigration the other way: when The Late Late Show (Ireland's longest running chat show) did a segment on the new wave of Irish emigration, Poland featured among the old favourites America, Canada and Australia as a destination.
There is a lot of focus on how enlargement is or isn't Europeanizing our countries, but I wonder how many of those who take advantage of the free movement rights become "Europeanized". It's not completely clear if many of the recent immigrants are returning home - though that would be the experience in my area - but there will undoubtedly be a number who stay. Will they vote in the European elections? How far should we go in making the political and cultural worlds open to new comers?
And what is the future of enlargement? With the economic crisis and paralysis on the question of reform, the prospect of further enlargements are being treated more coolly, and as the EU has enlarged to encompass a greater degree of Europe, increasing numbers of people do not feel the "rightness" at an emotional level for more enlargement. Turkey is the obvious example of the arguments that can arise over enlargement, and how they can spill over into arguments about what "Europe" is and ought to be.
But for me the reunification feeling is still there.
* Though as some have commented before, white, Catholic Poles don't exactly pose much of a culture shock.