East and West cannot even agree on a common date for the celebration of Easter;  I am not optimistic on agreeing on theology or authority.  While Christ did ask that they all be one, I don't see any other benefit for the Orthodox churches to unite with Rome. Theologically, the Orthodox refer to RCs as heterodox, so before any union of the east and the west, there are theological differences to reconcile, which are as difficult to resolve as the role of authority in a "united" church.