I know this will sound very cynical, but I think very few managers are actually leaders. I think a leader is someone sets a standard, a quality that others aspire to reach in excellence, a problem solver.
Unforntunately, in my limited runs in management-type positions, I was very dissappointed to find that nobody cares if you want to be a leader, the higher ups usually prefer "yes" men or women. I am not in any way saying all managers are not leaders or good at what they do. Just that the few I have seen who actually consider themselves a part of the same team as their staff, are usually given major grief by their higher ups.
I think that if I want to be a leader, I am better off at the "bedside" (of home health currently) as a mentor, or someday as a nursing instructor, a role model, rather than a manager. A manager has to do the yucky stuff like decide who will have to work Christmas, making schedules, etc... Not much need for leadership there. Now maybe the nurse managers who pitch in and help at the bedside have a good mix of both, but it is really a very delicate balance to achieve.