I used to work for a company in which employees in some departments would do 2 or 3 year "shifts" as managers. When your shift was up, you went back to a regular employee in the same department, and someone you had been managing took over. It was not uncommon to have a young manager, but not everyone was eligible, obviously.

I think it prevented the "us vs. them" mentality from creeping in, and I got the impression that most managers were eager to return to production work. There were dedicated managers higher up the ladder, of course.