I wouldn't be terribly surprised to see an aging Batman commit suicide by criminal.

Uhm, have you seen the Batman Beyond (http://imdb.com/title/tt0147746/) cartoon series? Because Bruce almost *does* get himself killed -- that's what prompts his retirement. And twenty years later Terry McGinnis gets ambushed by a Jokerz biker gang outside the Wayne Manor gates, and Bruce gets very, *very* irked.