I was just scanning the list of the most common baby names of 2000-2009, and noticed that David is 43, John is 44, and Thomas is 50. Of the most popular names from my boyhood, only Matthew (4) and Michael (8) are still common. William is 24, James 31. Even bigger change on the girl's side, where the highest ranked name I remember from elementary school is Sarah (11). Lisa, Laura, Anne and Michelle didn't even make the top 50, Elizabeth is 28 and Katherine is 41.
But I suppose that one day the wheel of fortune will turn again, Aiden and Emma will come to seem old-fashioned and silly, and the world will once again be full of young Johns and Lisas.