That shortlist in full

 You knew there would be leaks. That shortlist in full:

1. The Archbishop of York
2. The Bishop of London
3. The Dean of St Albans
4. The Reverend Richard Coles
5. ecumenically-minded, Benedict XVI
6. if His Holiness is busy, substitute Fr Z.
7. Why a cleric? Try Frank Field
8. by far the best qualified, the ubiquitous David Lindsay
9. for the full St Ambrose, Baroness Warsi

and realising that the law would have to be changed to allow the Baroness:

10. like a squarson of old, appointing herself, Elizabeth II