Alot of Polish people have left Ireland in the past few years. Heck, alot of Irish people have also left Ireland in the past few years! I read a figure a few weeks ago estimating the number of Polish people in Ireland but I can't find the article. I did find this article
from 2008 suggesting 'a third of Ireland's estimated 200,000 Polish immigrants plan to leave within a year.'
We still have Polish sections in our supermarkets and I think some newsagents still sell Polish newspapers.
Coronation Street isn't Irish and I don't know watch enough Irish tv to answer you're question, sorry.
Did you ever live in Ireland?