It is clear from watching the Holy Father lately that he is in decline. He is now wheeled into St. Peter's on a platform just as Pope John Paul II was at the end, because he is no longer able to walk the length of the aisle. His voice is noticeably weaker, and he has that sort of "far away" look, like a patient in a hospital bed often has. I wonder if he may not depart soon due to natural causes, never mind by an assassin's bullet.
It's anybody's guess who the Sacred College would elect to succeed Pope Benedict, of course, but-- if it is not in extreme bad taste to contemplate possibilities at this point--my own best guesses would be Cardinal Canizares, the former primate of Spain, or Cardinal Scola, the Patriarch of Venice. Some say Cardinal Ouellete, but I have trouble imagining a Canadian pope!