Two of the toughest challenges for any company are leadership transitions and rapid growth. How do you replace an enormously popular and beloved CEO? And how do you maintain a rapid growth rate without losing the culture and focus of a small company? Over the past ten years, since the death of the legendary Sam Walton, Wal-Mart has passed both challenges with flying colors. It's now the first company to rank number one on both the Fortune 500 and...