One week before Gen. David Petraeus is expected to give his report on U.S. progress in Iraq, CBS Evening News anchor Katie Couric says she has already seen dramatic improvements in the country."We hear so much about things going bad, but real progress has been made there in terms of security and stability," Couric said Tuesday. "I mean, obviously, infrastructure problems abound, but Sunnis and U.S. forces are working together. They banded together because they had a common enemy: al Qaeda."Couric traveled to the city of Fallujah in Anbar province, which U.S. forces entered in April 2003 and again in November 2004. That is the same city where, in house-to-house fighting, American forces uncovered nearly two-dozen torture chambers.