On a serious note...It's not really a power issue. It's more of a leadership issue. Mentor's are a great leadership aspect of SitePoint in that they are trusted with a degree of the leadership of the community. We all participate primarily in one of the four Sitepoint teams: Build, Grow, Tools and Community. We are chosen, not simply because of what we can do, because there are alot of skilled people out there that could be mentors on that basis. There's more to it though. We are also chosen by our ability to lead.
As a sidenote, a good perspective on leadership is something that is taught to the leadership in the church I attend. Leadership is not power but it's influence. That applies here too. A mentor is chosen as a mentor not because of who he or she is, nor simply what they can do but because he or she is already a mentor without the title. The person is already demonstrating the ability to teach, learn, help and push SitePoint in an all around good direction. In those instances when a new mentor is nominated, the existing mentors are acknowledging so and so as a mentor.
I say all this to say one thing that has been said in several other "how do you become a mentor" threads. Members, pay attention. A potential mentor must demonstrate not only good knowledge in one of the four areas listed above, but they must demonstrate a good attitude, ability to communicate effectively with others, and a team player (the Sitepoint team).