Excellent article in WSJ on the charateristics of entrepreneurs. This reminded me of the great book Founders at Work. It is a series of interviews with Tech Founders from Sabeer Bhatia founder of Hotmail to Catrina Fake of Flikr. If one theme came across consistently, it is that most of them executed their plans and worried about consequences later.
I think the biggest hurdle of moving from a corporate job to a startup mode is that in the corporate world, employees especially managers have to make extensive plans, budgets, risk migation strategies and in a startup by definition you cannot mitigate the risk. Something either works or it fails and you pick yourself up and start again.