Berkshire Hathaway chairman and world's second-richest man Warren Buffett said Tuesday that his $34 billion purchase of Burlington Northern Santa Fe Railway is a bet on America's future. It's a bet, but not just on America. With the investment, Buffett is also betting on China's rebound and growth, the price of oil going back up, the continued use of coal to make electricity and a higher profile for the nation's railroads, thanks to a push from the White House. Join discussion...