Well, first of all, Congratulations to Prince Akishino and Princess Kiko! Expecting a baby is a great thing, regardless of age, and I trully hope that they will have a healthy little kid.
I was very surprised to learn about Princess Kiko's pregnancy and my first thought was 'what will happen to the succession reform now?' I am very fond of Princess Aiko and would love to see her as the Empress of Japan one day. However if Princess Kiko deliveres a boy, then I really think it would be better if he were the heir. I say this not of my personal believes, because as I said, I am very fond of Princess Aiko, but taking into consideration the traditions of Japan, which must be respected. I do think that most Japanese people would prefer a male Emperor, because that's part of the tradition and traditions still play a great role on Japanese society. And any traditions must be respected.
Anyway, putting the succession reform aside, I again wish Princess Kiko to have a healthy, lovely little kid, a boy or a girl.