I always find these cases a nuts.  If it wasn't for modern medical methods we the body of a brain dead person could not be kept from rotting away.  

If you don't accept brain death as a definition of death fine - but then don't insist that a person be hooked up to a machine that keeps them breathing and a feeding tube when their brain can't signal the body to breath.

A body can be kept breathing for a long time if the machine is doing it for them but if the brain is not there what is the point.  I have been told that it is up to GOD to end the persons' life.  Fine - disconnect the machine and if GOD wills it they will live.