There are only currently three countries that use a measurement system other than metric-- Liberia, Myanmar and of course, the United States of America.
Making the metric system the standard in the United States would renew interest in math and science. When something is more understandable ( no converting of imperial to metric) there may be more interest in those types of careers. We need young people to take an interest in math and science if we expect to remain competitive on a global scale.
Most consumer products and about 50% of measures in the US are already metric. We are doing ourselves and our children a great injustice by not giving us this edge in these areas.
Metric Conversion Act of 1975--in effect but not active
http://lamar.colostate.edu/~hillger/laws/metric-conv.html