As soon as I finished the previous message, I received an email with TERC's official statement about the US DOE review. It's similar to what I just wrote, but here it is:
"The U.S. Department of Education has a new publication which showcases what a panel of experts has selected as exemplary and promising mathematical programs called Exemplary and Promising Mathematics Programs. Several years ago when the Dept. of Education sent out its invitation to submit to this, the staff of Investigations decided not to submit. The kind of evidence of student achievement DOE required was not yet available given the short amount of time the curriculum had been out. In fact, the entire curriculum was not yet published at that time. Now several studies have been done that do show excellent results in student achievement in classrooms where Investigations is being used. The results of the studies are available on the Investigations website, and a brochure detailing these studies will be available soon (contact the Investigations Implementation Center). The Investigations Implementation Center is currently collecting further data from school systems which have been using Investigations as their complete mathematics program for several years. If there is another opportunity to submit to this program, we probably would now choose to do so, but we were simply too "young" to do so at the time."