If you go into the Business school, you will be learning more than theory. It is meant to prepare you to go out into the real world, for you to learn practical business skills. Yes, you could make the next ebay or facebook, which you don't need a degree to do, but I wouldn't bet my money on it. Also, who cares what others think? Do what is best, but be smart and realistic. If you get a degree, chances are you will make more money later on, and you may be regretting not going to college. But don't let money be your main motivator, but definitely weigh that as a factor. Decide how important that is to you. So make the choice, and get advice from people you respect, and if you believe in God seek the answer from him.
Also, cyanide may be saying that due to the current economic crisis, that it isn't the best area to go into. That is a valid concern, but none of us know what is to come, an education can be a gamble.
And to answer your final question, it depends on the type of business you are going into, (you could always start your own business) but for the most part, yes, you do need a degree. No firm is going to hire you without a degree. Also, even if you want to start your own business, it will be easier with a degree, since it will be easier to get a loan from the bank, and you will have a better idea of what you need to do.