Has there been any official estimates on U.S. casualties?  I know the Army expects to 'lose' 10% of its tank force for every 100 miles it travels.  Heard that figure on the news.  News said the Army has plenty of recovery vehicles though.  When it said 'lose' I think they meant due to mechanical failures.  M1s are notoriously bad at using up spare parts (cost 4 dollars in spare parts for every mile an M1 travels).
In the last war, the U.S. suffered 150KIA.  35 were due to friendly fire.  I imagine the rest were mainly aircraft crews.
Only thing I have read is that many thousands of purple hearts have been ordered, and that 70,000 body bags have be ordered also.  Mainly for Iraqis I bet though (seriously).
I estimate fewer than 300 KIA, with about 25% due to friendly fire.