This story seems to me to be likely to attract a lot of political interpretations.
The pro-war people are already blaming insurgents, while Sunni Arabs in Iraq tend to think that Shiite Arabs are the culprits.
I suppose that either story could be correct; it is definitely possible that Sunnis who reject the legitimacy of the coming December 15 elections attacked him as a traitor because his brother is running for office.
On the other hand, there have been a lot of reports of Shiite Arabs killing Sunni Arabs and there is definitely a lot to be gained by the Shia by frightening the Sunni Arabs into not particpating in the elections (thus handing the Shia an even greater majority in the parliament).
In any case, I doubt that most of the Sunni Arabs will blame the insurgents instead of the Shiites, regardless of what the truth is.
I recall hearing on some talk-show host on the radio (I think, I might have read it on the internet, but I seem to think I was listening to John Gibson on the Tony Snow Show) saying that the terrorists (in which he implicitly included the Iraqi insurgents) were finally alienating the Iraqi people enough that they would lose support (I think it was in reference to the bombings in Jordan). As their major supporters were Sunni Arabs, targeting coalition soldiers might not cost them support, and targeting Shiites might not cost them support, but now that they were targeting Sunni Arabs, ooo boy are they in for it now!
I have a feeling that a lot of people feel this way about such attacks as the one references in the article. Unfortunately, this assumes that the insurgents are the ones responsible, and more importantly, that the targeted Sunni rabs will assume that the insurgents are responsible. If in reality this is an instance of shiite retliation for the years of oppression under the Baathists, or even if the Sunnis just think it is, this is likely to increase, not decrease, support for the insurgency, or at the very least increase the animosity between the different factions in Iraq.
I think reports of the insurgents' alienation from the general populace are greatly exaggerrated.
That is all.