Abu Musab al-Zarqawi has been killed following a U.S. airstrike Wednesday evening. The effects of his death will hopefully prove an inflection point for progress within Iraq. While any attempt to hypothesize who provided the intelligence for the attack would be highly speculative, I'd like to suggest one possible reading of last evening's events.
The government in Iraq currently stands at a crossroads. The biggest concerns right now are money and power, and how to guarentee each for all three ethnic groups (the Shia, the Sunnis, and the Kurds). For a variety of reasons, the Sunnis are structurally in the weakest position. First of all, they are the only group without oil in their region of Iraq, while both the Kurds in the North and the Shia in the South have oil in their respective terrorities. Second, the Sunnis have a relatively small population compared to the Shia, thus threatening their security. Finally, the Shi'ite/Sunni conflict extends beyond Iraq across the entire Persian Gulf, encompassing Iranian sponsorship of Iraqi Shia as well as Sunni jihadist support of Iraqi Sunni; Iran has certainly gone to greater lengths in their aid to their respective Iraqi faction.
While the final factor has proved to complicate the negotiations immensly - by bringing Iranian interests firmly onto the Iraqi bargaining table - it has also provided the Sunnis with their one source of strength and their trump card: the insurgency. As long as the insurgency raged, the negotiations could not ignore Sunni interests, because of the implied threat that the insurgency could strengthen or weaken based on the actions of Sunni leaders. This threat, however, requires the assumption that these Sunni leaders can control the insurgency. This is not necessarily a correct assumption, and cannot be taken for granted. If the assumption is incorrect, and the insurgency will rage on regardless of concessions made to the Sunnis, then it makes no sense to give them any concessiosns at all, and Iraq would likely fall into civil war.
Negotiations can proceed for some time while making the above assumption. However, they cannot proceed indefinitely. Stratfor specifically predicted that "by July 4 there either will be clear signs that the Sunnis are controlling the insurgency -- or there won't." In other words, either the Sunnis prove their worth, by decreasing the intensity of the insurgency, or they prove that they are, in fact, worthless.
It is in this context that the death of al-Zarqawi should be viewed. While I have no evidence to back this up, I would like to suggest that al-Zarqawi was a gesture, made by Sunni leadership, to prove their worth to the negotiations, and to guarentee their position in the new government. Stratfor has repeatedly pointed out the big difference between nationalist insurgents and foreign jihadists. The jihadists require the support of the local population, where "they are provided with food and shelter, and the village and neighborhood network warns them of enemy approaches." The ability to withdraw that support is the key to the current and future stability and power of the Sunnis.
If the Sunnis wanted to make a gesture of goodwill and a display of strength, they could not have chosen much better of a peace offering than the head of al-Zarqawi. The timing - so close to the fall of Somalia's capital city, Mogadishu, to Islamic fundamentalists - would certainly support the assertion that al-Zarqawi was a present, asked for by the United States, and given by the Sunnis of Iraq.
Update: Stratfor posted a new article on their website an hour and a half after I posted this one. "It appears that Iraq's Sunni political leadership has demonstrated the willingness to deliver on a U.S.-brokered deal to solidify the political arrangement in Iraq." I got worried when the first article didn't mention the Sunnis at all that Stratfor was slipping. Glad to see I was wrong.