This could allow a previously uncommunicative person to make decisions about his treatment. Including the cessation of treatment, if that is his desire.
But this horror of starving/dehydrating people to death so we can pretend we aren't killing them has got to stop. If we kill people, we should at least have the balls to do it using a humane method.
BTW, this used to be unofficially handled more humanely all the time, using overdoses of morphine, etc. But our present litigious society has made this impossible.
Thanks for the ping!