President Obama - Steve Kroft questions the president on a wide range of critical topics, including his performance in office, the U.S. economy and unemployment, and the budget woes in Washington. Howard Buffett - Legendary investor Warren Buffett has chosen his son Howard to succeed him as head of his multibillion dollar holding company. But as Lesley Stahl reports, "Howie" - a farmer - is no chip off the old block.