influential - as the most followers?
I would say not necessarily in number of followers so much as in capacity to influence international opinion and world events, hence Osama.
(EDIT: The list is designed to recognise "the men and women whose power, talent or moral example is transforming our world")
I would have to agree with Time here that he is single handedly responsible for changing the world.
Hitler was influencial in the same way.
Kate Moss is listed under 'artists and entertainers"; along with Brad Pitt and our own Cate Blanchett. My guess is as good as yours prometheus.
Anyway enough. I have work to do, deadlines to meet....