I'll second that. The worst I've seen have always been engineers or developers who felt that seniority, in terms of years on the job, entitled them to a management role regardless of any ability or training for it. They inevitably engender a tremendous amount of friction and resentment in their peers and subordinates.

As for younger developers, I manage several right now. Showing them that a management role isn't about "bossing people around for the sake of it," but more about handling different areas of responsibility needed for projects to succeed - some technical, some not - really works.