With Microsoft buying a piece of Facebook last week, the valuation was set at $15 billion. Not bad for a student entrepreneur who viewed his campus an an ecosystem and as a market to launch his business. Zuckerberg is hot and keeps getting hotter, but it remains to be seen if he can reach the heights of the biggest (by company size) campus entrepreneurs like Bill Gates, Michael Dell, and Brin/Page. BTW, the value is 1/2 to Fedex and 1/3 of the way to Yahoo.