Just to take fuji's side here, I think that if the article is correct, then the federal government has done something clearly wrong.
The articles says, quoting the government lawyer, "same-sex marriages are legal in Canada only if they are also legal in the home country or state of the couple." So that means that all the same-sex marriages performed in Canada for US citizens were never valid in the first place.
The article also says that same-sex marriage was "promoted by the provincial and federal governments". If that's true then the feds were claiming that the marriages in Canada were valid at the time, which is the exact opposite of what they are saying today. If the feds were promoting same-sex marriage to US residents, hoping to cash in on the tourist dollars, then it is reprehensible to deny those marriages later, once the initial influx of tourist cash died down.
Also, although the same rules would apply to heterosexual marriages as some have pointed out—specifically, that heterosexual couples also cannot get a divorce in Canada unless they reside here for one year—the effect is not the same, because heterosexual marriages are readily available in North America and so American heterosexuals don't shop around for marriage destinations and don't come to Canada expressly for that purpose. The federal and provincial governments profited from the differences between the laws in the US and Canada, and now Canada wants to turn around and say that those differences don't count. The government really misrepresented its law to same-sex couples in a way that they did not for heterosexual couples. So there is real unfairness here.
This isn't simply about the right to divorce, because the feds are denying the validity of the marriages of the US residents. It is problematic for the feds to make that argument because it is for the provinces to make laws about the solemnization of marriage, and for the feds to make laws about marriage and divorce. Obviously there is overlap and there is an issue as to who has jurisdiction. The federal government lawyer has made a claim about the validity of the marriages and that gets very messy in terms of jurisdiction. So if the feds continue to make that argument, that is a point on which a court could say that the feds are wrong, depending how they interpret the division of powers. To my memory, all of the legislation validating same-sex marriage is provincial, so there is a strong argument that the feds cannot deny these marriages.
So fuji is right, this is a sneaky way of invalidating gay marriages that were obtained by US residents. Harper can take advantage of the fact that the jurisdiction for the solemnization of marriage and divorce is divided, and invalidate some of the same-sex marriages performed in Canada by "doing nothing." But I don't think Harper is doing nothing. Harper is taking action if the feds are in effect saying that the marriages are invalid for US residents, because, assuming the article is correct, this is a change in the fed's position, and it may be an usurpation of provincial jurisdiction.
Now, it is for the feds to change the divorce law to waive the one-year residency requirement (before obtaining a divorce). This would solve the problem. But, as I see it, this is the feds changing the divorce law, clearly their proper jurisdiction. Whether they should have anything to say about the validity of marriages is much less clear.
And frankly I share the skepticism that Harper would make a special exception for these same-sex marriages, or simply abolish the one-year waiting requirement. I think it would show a lot of class to simply create this exemption.
And I think the courts can take action here too. The courts can say that the feds don't have the jurisdiction to decide on the validity of the marriages (or they could go the other way). The courts could also accept a novel argument that recognizes the fact that the government made representations that same-sex marriages were going to be valid for these same-sex marriage tourists.