“Vietnam: The Next Generation” profiles eight young achievers who “represent the changing face of Vietnam,” says narrator David Lamb. The biggest change is the introduction of capitalism into this socialist society, and one subject, the Harvard-educated son of a former South Vietnamese official, runs a business in Hanoi. But another works on a government project to turn the Ho Chi Minh Trail into a highway. Lamb, a former Los Angeles Times reporter, is married to filmmaker Sandy Northrop.