I would have reading materials and good hand lotion on hand. Washing up all the time is hell on the hands! Your baby won't need clothes at least at first, but will probably be wrapped up in blankets, so you might like some cute tiny baby blankets instead of the institutional ones. Read up on kangaroo care. Get your son some books on preemies. There are several on Amazon that are written for kids your son's age. Have you lined up a hospital grade breast pump? Your new baby won't be taking large amounts of milk, at least at first, and it would be a shame to waste any. Besides, with a little one at home, you may not be able to be at the hospital for all the feedings, so you'll want to make sure that there is milk there. I hope your son will be able to see his new sibling at the NICU, but I can see their stance on keeping at siblings. Little kids are germ factories as it is, and if there is anything new they could be carrying... I have read that many NICUs do tighten up visiting during regular flu season, so it makes sense that Children's would do the same for h1n1. Those who have died from h1n1 have had underlying health issues, and just by virtue of being born so early, your little one will have health issues. It varies by degree, but at this gestational age, there will be something (otherwise, they'd send him home right away). Even 'simple' colds can be life threatening to preemies. It may seem draconian now, but when your little one gets here, and has to recover from surgery so soon after birth, it will make sense then. How is Children's NICU set up? Is it individual rooms, or are there many babies in one large room? Frankly, that would make a huge difference in how far you want to push the visit issue. If there are many babies in one room, the NICU will have to be stricter than they would otherwise. You'd want them to be, frankly. You don't know what the older siblings of the baby 10 feet away from yours have been into. On the other hand, if each baby has his/her own room, your nurses may be willing/able to bend the rules for you.
What special plans have you got in place for your older son? Special gifts "from the baby"? Maybe someone can take him shopping to pick out some things for his new sibling? Perhaps he can be taken somewhere while you are in the NICU (if it was my 4 year old son, trips to see tractors or trains would be what I would look for.) - any thing the baby can not do. You want to drive home the point that there are benefits to being to the big kid now.
Will your son be at RMH with you? We have used the one in Madison, so I know how they work. There will be toys and movies for your 4 year old to use. There may (not always available) even be toys he can keep. Does yours have a playground? There will be a wide variety of homemade foods available and, while they can not babysit, will probably be lots of grandmotherly volunteers who will absolutely love to chat up your son about being a big brother.
FWIW, if you really *were* to go into labor anytime soon, you will probably be looking at a minimum of a 6 week stay. It dose sometimes happen sooner, but it is the rare baby who is able to go home before 35 weeks gestational age, and yours will have to recover from surgery, which is going to slow things down initially.
I hope this helps, and I hope you get to stay on bedrest a long time!
Paula - wife to Mike, mom to Zoey and Zander