I am a nurse at a birth center. Here's what I would recommend (in addition to what you are bringing).
Hairband to keep your hair out of your eyes.
Your Dh should actually be the one to pack the bag, since he is going to be the one digging through it trying to find everything.
Change of clothes for dh; if he gets a legful of amniotic fluid or a chestful of vomit, he's going to want to change clothes. Also, if they have a tub, have him bring his swimming suit; he might want to get in with the baby after the birth.
He needs a toothbrush and deoderant, too.
Camera, film, and batteries.
Babybook--the mws and assistants can sign it, and they can put the baby's foot prints in there, if you want.
Bottle of wine, if you wish (I always like it when people bring this
, usually there's enough for everyone to have a sip...).
Hope this helps!