Not only will the Irish Supreme Court have the opportunity on the appeal in Mahon v Keena  IEHC 348 (23 October 2007) (discussed here and here by Daithí) to discuss the constitutional protections, if any, for journalists’ sources, but I learn from The Court that the Supreme Court of Canada will also have a similar opportunity this term on the appeal in R v The National Post 2008 ONCA 139 (CanLII):
The Supreme Court is set to decide whether confidential sources for newspaper reporters are entitled to a claim of privilege similar to that of confidential police informants. The case of National Post v. R. … will settle a long-standing grey area in Canadian media law, but to get there, the SCC will be asked to mediate between the conflicting public interests of investigating crime on the one hand, and the freedom of the press on the other. …
The Canadian case turns on whether a journalist can assert privilege over a bank document received from a confidential source which disclosed highly incriminating evidence of a conflict of interest by Prime Minister Jean Chrétien in a property scandal which the bank and M Chrétien claimed was fabricated. In R v McClure 2001 SCC 14 (CanLII), (2001) 151 CCC (3d) 321 the Supreme Court said that the confidentiality of the relationship between a journalist and the journalist’s source may be protected on a case-by-case basis. However, in applying the test set out in McClure, the Ontario Court of Appeal held against the privilege in The National Post case; in particular, on the question of whether the injury to the relationship between journalist and source from the disclosure of the communications is greater than the benefit gained from the correct disposal of the litigation, the Court focussed on
the fact that his document was potentially fabricated to stir up controversy surrounding the Prime Minister of Canada, … [and] found that the benefits of getting to the truth were ‘overwhelming.’ The interest in protecting confidential sources, meanwhile was ‘attenuated’ by the fact that in this case the media was “shielding a potential wrongdoer from prosecution for a serious crime.”
The outcomes of the appeals will make for an interesting pair of cases, not just in relation to the similarities of fact but in particular in relation to the law on journalists’ sources.