Hagel has an important post here about the special challenges the social web poses for people who are shy. And how passion might be one way they can cope with it.

...In this new world, shy people can be at a significant disadvantage. We run the risk of becoming increasingly stressed and marginalized by the extroverts who welcome the opportunity to broaden and deepen relationships. They thrive in crowded rooms while we are deeply uncomfortable with exposing and sharing....

...In sharp contrast, passion holds the key to creating and shaping relationships that will help us thrive in a rapidly changing world. It motivates even the shyest of us to reach out and connect with others in ways that become catalysts for creativity and growth. Passion fosters a uniquely strong and productive bond that provides both the stability and stimulus needed to continue to grow and succeed in a constantly changing world....