Consciousness and identity

This week's Nature has a story about restoration of consciousness to a person in a "minimally conscious state". What I understand of the approach is that it involves stimulating portions of the brain that enable a rebuilding of consciousness. The story raises a lot of exciting and troubling ethical questions for me, on both sides of what one might call the Terri Schiavo Fissure in popular thinking about medical ethics. Obviously one implication of the story is that people who would previously have been allowed (or encouraged) to die are actually candidates for recovery of a sort (and it's easy for a naive reader like me to extend that hope to the next category of unconsciousness on the way to total nonexistence, the "persistent vegetative state" that was actually Terri Schiavo's, though I should stress that the authors of the Nature paper, or rather the popular review of the paper that precedes the paper itself, and which I actually read, are emphatic in stating that nothing discovered in this therapeutic method would extend to the persistently vegetative), making it more difficult to decide when to pull the plug on someone, or to plan to pull the plug on oneself (and by the way, I join Richard Poussette-Dart in the category of people who do want extraordinary measures taken to keep me alive if it should come to that). But there's also the question that should circle around scorpion-like to bite the fundamentalists, which is whether the consciousness restored is the same identity that was previously lost, even at this stage in the development of therapies, and whether if there is no common identity there can be said to be a common soul before and after the loss and recovery. I don't know whether any personal memory accompanies the restoration of consciousness from the near zero state of minimal consciousness, but what if there is none? Would the nexus of relationships with people whom one finds waiting for one's recovery be enough of a system of memory to qualify as a persistent identity? It's as easy to construe the Nature story as an argument against the existence of the soul as it is to construe it as one in favor...