Entrepreneurship MBA programs are all the rage these days, but do they really help? Forbes points out that only 15% of the wealthiest 400 Americans have them. I'm not sure that is a relevant statistic though. Henry Mintzberg makes a good point in the article:
When it comes to starting companies, the stumbling–not the studying–is what counts, argues Henry Mintzberg, author of Managers Not MBAs: A Hard Look at the Soft Practice of Managing and Management Development. Bona fide entrepreneurs such as Bill Gates and Apple's Steve Jobs typically shun M.B.A. programs because they're too anxious to work on their own ideas, says Mintzberg. (Both Gates and Jobs dropped out of college to start their companies.)
A valid insight, but one that still doesn't directly answer the question.
Jeff Cornwall has said repeatedly that entrepreneurship training can make a significant difference in success rates. On the flip side, a local angel investor once complained to me that he was tired of these 20-somethings coming out of school with their entrepreneurial MBAs thinking they were ready to start up a company. He thought that most of them weren't.
It's probably somewhere in the middle, and equates well to an exercise analogy. Some physical training will make you better, regardless of where you are, but you need more than that to make it to the Olympics.