It is amazing what a difference it makes in the life of a leader, and for the morale of a team, when negative, noncontributing, and nonproductive people 'go away.' For a variety of reasons, letting go of these people isn't always easy; sometimes there is red tape, sometimes there are close personal relationships, and sometimes there are feelings of obligation or remorse. What great leaders do, however, is fight through whatever barriers exist because they know the future outcome is better than the current condition.
It is also important to remember that everyone is replaceable. It might not seem like it at first, but trust me, you have not see the last, greatest __________. It will take time and training, but if someone is making your leadership difficult, don't let their talent be an excuse for not dealing with them appropriately. The 'Terrell Owens' of the world kill too many otherwise excellent teams.