I am all for child-led weaning, but I fully realize that we may need to initiate night weaning during pregnancy if I don't get enough rest. I am not a nice mama when I am tired!
I am still nursing 29 month-old DD, who nurses every three hours or so. I have to eat A LOT (3,000 to 4,000 calories per day) suddenly, but I love being able to rest every time she nurses. Of course, the nipple twiddling may have to go soon! Either she has suddenly started climbing all over me, or else it has only recently started bothering me. I am having trouble being a nice Mama all the time.
ETA: Yes, I plan/hope to tandem nurse. DD is SO excited about the baby and has big plans to share all of her toys and hold hands with baby while getting "milkies". Hopefully she will be as thrilled when baby actually arrives.