We are in the season of anniversaries - Elvis, Diana, the World Trade Center. August 16th 1977, August 31st 1997, September 11th 2001. If the comparison is trivial and demeaning, don't blame me. Five years ago, my mistake was to compare Diana to Elvis - or Marilyn, that other tragic blonde icon whose candle-in-the-windiness was transferred to the late Princess and promptly became the world's best-selling single ever, dethroning Bing's White Christmas. I thought her lustre had the staying power of the other big-time celebrity demises. I was wrong.But grant me at least a sense of proportion: The throngs howling...