It is likely that you will remain Irish resident for 2010, unless you are in Ireland less than 30 days in 2010. If so, you will be taxable in Ireland on your UK income in 2010, but with a credit for UK tax paid.
You could also be UK resident, but probably Irish resident under the treaty. You would therefore be taxed in the UK on UK arising income.
You will therefore have to complete tax returns both in Ireland and the UK for 2010.
However, if you leave Ireland for a good period of time, you may break Irish residence and may be able to claim split-year relief.