People are still finding Nazi WW2 caches in Europe (it just doesn't make the news). Losing armies have a long history of leaving behind ordnance that they couldn't fire.
Heck, in the past 5 years I've seen at least one article on U.S. civil war ordnance (C.S.A.) from the 1860's being discovered in the South!
Understand. Sadly this time around much of the stuff may have been buried prior to the invasion for supporting the Saddamist resitance. One things for sure having an estimate forth or fifth largest ordanance supply of all nations they sure have a lot of stuff still probably still buried. Let alone what may be buried in the form of chemical pre-cursors for nerve gas etc..