An interesting post by Xconomy on the topic. It’s been a on-going topic and there are no clear answers.
Check the post at Can Business Schools Teach Entrepreneurship?
In “vibrant ecosystems” such as Route 128 and Silicon Valley, business schools are embedded and students easily find or develop ideas. But I am less sure Business Schools really teach. They explain, they expose and of course they teach management. As I comment on that post:
There is a talk by Prof Byer (Stanford) about the Silicon Valley and Stanford ecosystems, where the author claims about 5% of companies are direct transfers of technology:http://spie.org/documents/Newsroom/audio/Byer.pdf
It is not clear how many companies Stanford alumni have created. At least 2′500 but probably many more. Now the role of business schools is another subject of interest. You have stories on both sides, i.e. pure engineers or scientists (Google, Yahoo, Cisco in the academia, Apple outside) or entrepreneurs from bus. schools (Sun Micro, eBay).