if the current American casualty rate over the last 5 months in Iraq stays the same, more American soldiers will have died in Iraq than all the civilians that died in the Twin Towers.
Details on casualty rates are at this site.
I first wrote about this on September 7th, when the cross-over date was March 2007. Average American casualty rates have become worse since then. Maybe they will get better in the next 2 years, but we've heard that song before (getting better at the end of major operations, when Saddam and his sons are captured/killed, when sovereignty is turned over to Iraqis).
P.S. Can't leave out the token mention of massive Iraqi civilian casualties, far above what the US suffered, although it has no political importance here in the US.