(FYI - I'm probably just reiterating what others have said, but I'm lazy and don't want to properly cite by finding all the "should you go to college" blog posts / comments...)
0. Staying in school doesn't hurt. College is a four year block of time where you are encouraged and expected to experiment with every aspect of your life. This experimental space can't be found anywhere else. (The financial aspect is a different story; if going to college puts you in a huge amount of debt, this point may not be true.)
1. Know that you can always dropout. I take comfort in this fact. If I come across a life-changing opportunity, I can always just postpone college.
2. Theory != Practice. When I first started studying CS at school, I was peeved that professors didn't optimize code as much as possible. Why should I disregard the constant for a linear time algorithm? However, I've since come to appreciate the generality of this method of thinking. Thinking generally about specific problems is (to me, at least) a valuable skill to have and one that I need to work on.
3. It's not about the classes, it's about the people. This is an old but important argument and it's completely valid. You'll learn way more from your classmates than you will from your professors. It doesn't matter how great of a coder you are... if you don't learn social skills you'll be a terrible entrepreneur.
4. Professors are really smart. At any decent university, you'll have access to a group of people who have spent their entire careers being clever. Most are more than happy to explain their work / mentor an interested student / try to impart some cleverness.
5. A three-month summer. The fact that summers are exactly three-months is a good thing. If they were longer, students might not return from really wonderful jobs. If they were shorter, students wouldn't be exposed to jobs long enough. By taking full advantage of summers, you can "job hop" and sample careers / businesses in a way that would be otherwise frowned upon. I've learned a lot about how I would create company culture by working at different companies, and I still have three more summers to keep learning.
6. Keeping relevant paths open. Entrepreneurship has always sounded attractive to me, but I'm curious about a lot of things. I'd rather be positive about the career path I choose than always wonder if I should have done something else with my life. By trying out research / acting / underwater basket weaving now, I can either decide certain professions aren't for me or find a way to incorporate them into my eventual line of work.
7. Recruitment. From a purely economic, slightly perverse perspective, college is a great place to recruit for a future startup.