Interesting points, Kittens. On the women's side, surface isn't quite the equalizer (dubious term, I know) that it is on the men's side. It's funny because even though you think of many top players on both sides doing worse on clay, it still means a variety of winners. However, it seems like every woman has one that she wouldn't win. I couldn't see Lindsay or Maria winning the French, I couldn't see Kim or Justine winning Wimbledon, etc. But with the right draw and a couple injuries, who knows. Lindsay has reached the semis at the French and Justine has reached the finals at Wimbledon.
FYI, Since 2000, this is how many different women have won each slam: