"TWENTY-FIVE PIECES IS NOT THE SAME AS 170,000."
"Loss Estimates Are Cut on Iraqi Artifacts, but Questions Remain" (New York Times via Iraqcrisis)
The bottom line is that fewer antiquites were lost from the Baghdad Museum (and elsewhere) than originally thought, although no one yet knows what the actual number is. Some items have been returned by looters and some were removed by staff before the war and are in safe hands. The actual number is somewhere between the extremes given above. I hope it turns out to be closer to the lower number!
Also, check out this site from the University of Pennsylvania Museum of Archaeology and Anthropology:
The Cultural Heritage of Iraq