facebook to sell for $2 billion?

BusinessWeek is reporting that Facebook is up for sale for $2 Billion, after the founders turned down an offer a $750 million. This is only about 2 years after the site was built as a sopohomore college assignment. The site is now the 7th highest ranking site in terms of monthly page views, and had over 37 million unique visitors last month. If it sells, it would make 4 guys very rich before they EVEN GRADUATE COLLEGE (or at least reach that age).