Well, I think it takes more than a cute face, a brilliant mind, a decent accent and a tiny, sweet speech impediment to fit into the footsteps of Sir David Attenborough. If this would be it, my preferred choice is Lisa Randall. (She also has the »right« sex—at least for me.)
But to add some hard facts: Sir David Attenborough’s contribution was mainly in the field of the life sciences which has all to to do with ourselves, as we all are living beings. That’s why we feel so involved in the stories he told us about our fragile, »living planet«. Physics seems to be away from our everyday experience—although I certainly know that this is not true.
On the other hand, I feel it is unfair to handle not only the torch, but also the shoes from another man. It would be best to leave it to Brian Cox to lead his own path of enlightenment. I love new stories to be told. And he is still young.
And yes, the films I have seen with Brian Cox have a kind of shallowness which I dislike. But I am no ordinary person, I still watch lectures—not only edutainment.
In fact, in this mini-series he has done a great job combining his world of physics with what matters most for us—life.