There is an ongoing debate about the differences and definitions of leader and manager and many are striving to identify which is better. The bottom line is, organizations need both leaders and managers in order to be successful. In fact, the more "lean" organizations become, the more we will see leaders who need to be able to manage and managers who need to be able to lead.
One of the mistakes that have been made is trying to make management and leadership independent of one another. The truth is they are both dependent upon one another for a company's profits as well as their people's success.