
The Pope carries a donor card according to The Times, whilst L'Osservatore Romanum has a story about the Ponifical Academy of Sciences debating when the moment of death actually occurs.
The traditional moment of death was when there were observable signs of decomposition or rigor, up until when it was judged the sacraments could still be given.
The modern understanding of death is when brain activity ceases, after which organs can ethically be taken. The problem here is of course is the distinction between deep coma and death.