Interestingly, the Lancet survey result is no longer a crazy statistical outlier. A September, 2007 Opinion Research Bureau study arrives at an even higher figure of over 1,000,000 post-invasion deaths.

http://www.opinion.co.uk/Newsroom_details.aspx?NewsId=78

This study, instead of being hotly debated, is being largely ignored.

I don't think anyone knows the "true" figure. I am sure that any reasonable person would agree that the total documented deaths is surely less than the true number.

I suspect that many have no interest in the true number, and for political reasons will only admit to documented deaths (and even then, round them down).