I think Ben is still looking out for the best interests of the losties and the O6 even though the writers are going to great lengths to prove otherwise. I believe, once John told him about Hawking, he knew John really did have to die and that he would be brought back to life when they returned to the island. It's like he realized that John was working according to some master plan established long before any of this happened. I'm saying this because his whole demeanor changes as soon as he hears her name. Then, he takes the wedding ring to Sun because, even though John promised not to ask her to return, Ben never made such a promise and knows that she must return.