MORE THAN 16 MILLION STUDENTS are now enrolled in colleges and universities in the United States, the largest number ever. In two years, the figure will exceed 17 million, and it will continue to grow, as the high school graduating class of 2008 will be the largest in history. Today nearly 70 percent of the 18-to-24 age cohort attends college in one form or another, and more than 80 percent of high school graduates do so. College attendance has become a near universal rite of passage for youngsters in our society, and a requirement for entry into the world of...