I didn't read all of the responses, so I don't know if anyone said this yet, but I will DEFINITELY be packing my own heating pad. I had such bad cramping from the post-birth contracting that advil wasn't touching. I asked for a heating pad, and you'd have thought I asked for access to high-controlled substances! They had to get approval from my doctor, then approval from the head nurse, then they had to "order" one, then when it finally got there about 2 hours later, it ended up being a water heating pad that was attached to a huge machine that looked like a vacuum and it had to warm up (30 minutes minimum).
Other than that, I will be packing about what I did last time: toiletries, laptop, cozy clothes, makeup for visitors, advil, a bigger robe (I had a short one last time and I felt so drafty!).