I never got to have a sister, and it was something I really wanted. So I'm very very happy that DS is going to get to have a little brother!
Now, DH and I were both hoping for a girl, really, but I know it's going to be wonderful. Mostly, I'm having to adjust to seeing myself as the mom of two boys. For some reason, I never even imagined this! My brothers were very difficult babies/children, so it was always a really scary thought for me. But having DS, and knowing how awesome he is, it's not so scary anymore.