His theory : aspiring Silicon Valleys needs two things : nerds and rich people. Nerds are a subset of creative class. And want CC-type things, though with some particular emphases, more cafes and fewer clubs, more bookshops and fewer boutiques. Most important is a good university (or computer science department in the university). He thinks this is fairly easy for a city to achieve.
Money quote : you can't be somewhat of a startup hub. You either have a self-sustaining chain reaction, or not. (Silicon Valley is an AutoCatalyticNetwork of startups. People who work for startups go on to found more of their own. People who get rich from startups, invest in new ones. See PayPalMafia )
BoulderColorado : http://www.fastcompany.com/article/why-you-should-start-company-boulder