I agree - leaders can be anywhere in an organisation, not just in "positions of leadership". And organizations are the stronger for it.
In my team of 10 there are a few who show leadership abilities. There are occasions when I find this threatening "hang on a minute, I'm supposed to be the leader!", but mostly I have learnt to appreciate these skills and abilities and use them to further the team's aims.
I'm not necessarily a natural leader, someone with vision and persuasive ability, but I am a very good manager - good at helping my team grow, take initiative, and work with their strengths, so I see my recognition of, and capitalization on, other's leadership traits as a really positive thing in our organisation