In relation to the recent blog regarding the Damache v DPP  decision and search warrants, as expected the effect on already decided cases will likely be minimal.
In DPP v Thomas Hughes  (7 July 2012) a convicted person challenged his conviction on the basis that evidence used to convict him had been obtained under legislation which had subsequently been found unconstitutional in the Damache case.
The Court of Criminal Appeal rejected the applicant's appeal on the basis (amongst other reasons) that he had pleaded guilty during his trial. The State did not have to rely on the evidence which it had obtained by the means which were subsequently found unconstitutional.
This is in line with previous decisions such as the high profile decision of C.C. v Ireland  where a convicted person sought to have the decision overturned following a subsequent finding that the legislation outlining the offence was inconsistent with the Constitution. The court found that as the accused had not sought to challenge the provision in his previous trial he was not entitled to rely on it at a later stage