OBITUARY AS STAND-UP. Mark Steyn is a more-than-brilliant writer who can't resist quipping even as he appreciates. Thus he memorializes the recently departed with startling joie-de-vivre. Just consider this recent portrait of Ann Miller--and the earlier ones of Elia Kazan, Charles Bronson, Katherine Hepburn, Leni Reifenstahl and Sir Dennis Thatcher.