DS has been in preschool since he was about 2.25. He has *really* huge social needs that I simply couldn't meet with mommy & me type activities.
Since a few months after we moved, he's been in school a little longer. His old school was 3-4 hours a day, 3 days/week; the new one is 5 hours for a regular school day.
Then we started afterschool care two days a week so I could move my work hours around and work a bit more. So two days a week he's in school 7-9 hours. Except, this month, he's in school FIVE days a week, and in afterschool 3 days... so that I can get as much work in before I disappear on maternity leave.
That changes in April. We scale back to his original 3 normal days a week, and that starts almost two weeks before my due date. I stop working too. DH will be taking 8 full weeks off of work once the baby arrives. I think giving our *whole* family time to bond together, the four of us, is something DS will really appreciate (as much as he loves school, I can tell that he's missing us too). I expect he'll want to take at least a couple of days off of school right after the baby arrives, and he'll have that option (OTOH, he might want OUT of the house right then, which is his call ;-).
My mom's planning on getting him a portable DVD player of his own to keep him amused during labor. Not sure if we're going to get him anything else material. Mostly, I think that we're just going to roll in our little nuclear family, and make it clear that we're all a part of it.
His birthday is less than three months after baby's due date, so we'll have to make a heck of an effort to make sure that he gets a good celebration, too. Also, sometime after his birthday, he has to go to Disneyland again, because he'll FINALLY be old enough for the Jedi Training Academy ;-) (and geeks that we are, we plan to teach him the routine on our own before he gets there, so he has no problem beating the cr*p out of Darth Vader).