For David Weinberger from Berkman Center for Internet and Society at Harvard Law School, leadership in the past knew everything and leads by keeping information limited to their followers. Information "flowed up" to the leaders, at the top, the natural place for decision making. Now information is everywhere and available for everyone. This is a good time to rethink our ideas what leadership is and means. David Weinbergers journey at Le Web '08 starts with the statement "decision-making is a failure of leadership". The unnatural position of one man, knowing everything, at the top of the pyramid will come to and end.
He is arguing for decentralised forms of leadership in the 21century corporation, as an essence of Enterprise 2.0. Leaders are not longer isolated heroic figures when we allow for more emergent and crowdsourced forms of leadership. Leadership is a property of network, and this has also a consequences for politics. In his talk at Le Web '08 he also argues for reputational democracy vs. representational democracy.
[Update] Podcast interview with David Weinberger at "cruel to be kind" from Nicole Simon.