Johns Hopkins and The Lancet seem to be pretty substantial sources to me, how about you?

655,000 deaths is a staggering number. Even supposing that figure is in error by double, you still have well over a Quarter Million dead men, women and childeren to consider. Our country allowed our military to carry out this invasion based demonstrably on untruth after untruth. Even though I voted against this empire of madmen, it is still my country, and we are well into Pol Pot territory. (He racked up 2 million dead.) I am sickened.

Update below

Glenn Greenwald In Unclaimed Territory:

The news item that is certain to (and ought to) dominate our political discussions for the next several days at least is the report that "a team of American and Iraqi epidemiologists estimates that 655,000 more people have died in Iraq since coalition forces arrived in March 2003 than would have died if the invasion had not occurred." The findings are so extraordinary because of how radically they depart from other estimates:

It is more than 20 times the estimate of 30,000 civilian deaths that President Bush gave in a speech in December. It is more than 10 times the estimate of roughly 50,000 civilian deaths made by the British-based Iraq Body Count research group.

The report is being published in Lancet and was conducted "by Iraqi physicians and overseen by epidemiologists at Johns Hopkins University's Bloomberg School of Public Health." Nobody disputes that the survey used scientific methodology to reach its findings, although everyone recognizes there is inherent uncertainty in counting the number of civilian dead in a war zone, and even the researchers themselves acknowledge a huge margin of error. The same research team published a similar report in Lancet in 2004 claiming that 100,000 Iraqis had died, though this newest survey has a much larger and more representative sampling than the prior one.

Read on.

(Update)

Shakes at Shakespear's Sister:

Over 600,000

That’s how many people are estimated to have died in Iraq due to the war since the March 2003 invasion.

A team of American and Iraqi epidemiologists produced the estimate by “interviewing residents during a random sampling of households throughout the country. …The interviewers asked for death certificates 87 percent of the time; when they did, more than 90 percent of households produced certificates.”

The number is startling, and of course Bush supporters are already declaring it categorically wrong.

At issue is the methodology—“cluster sampling,” which is also used to estimate mortality during famines and after natural disasters. The methodology was assailed after the 2004 estimate of 100,000 casualties, objections which, Drum rightly notes, “mostly didn't hold water. (For example, they were accused of inflating the figures by including a cluster from Fallujah, which had just gone through a horrific battle. In fact, they specifically excluded the Fallujah cluster for exactly that reason.) This time around, the figures from their new study buttress the previous one, and also match up with other data, which suggests their methodology is on target.”

The researchers are also defending their work again, by noting that “The recent survey got the same estimate for immediate post-invasion deaths as the early survey, which gives the researchers confidence in the methods. The great majority of deaths were also substantiated by death certificates.”

More...