Per Melissa's request, here is a blog post on how our cats have adjusted. =)
When we very first brought the babies home from the hospital, the cats were both a bit wary of the babies. They had the same reaction that Chloe (our calico) had when we brought Noah (our tabby) home for the first time. They were a bit scared of the babies and didn't seem to sleep in our room any more, but they very quickly adjusted.
Within a day or so, the cats didn't think twice about the babies. Now, the cats sleep on our bed again. They don't even seem to mind when the babies cry, even if they are on the couch right beside them. As you can see in the above picture, the cats are happy to have some new napping buddies. Lots of napping happens at our home (except for parental napping, unfortunately).