Lots of good thoughts from the PP. We took our DS to WDW at 5 months, and then to DLR at 11 months...both times were great!
The only other thing I might add is to be sure and take a baby carrier. There are lots of places and rides that you can't take a stroller, and you'll definitely get tired of holding the babe, even if you trade off. (This was important on the buses, too.) So we took our Ergo, and when we'd get in line, we'd get the DS out of the stroller, and one of us would wear him in line. Also, ours slept much much better and longer in the Ergo than he did the stroller, for the most part. It did get a bit wearisome on my back though, so be sure and take lots of breaks. But we were even allowed to take him in the carrier at that age on lots of rides IN the carrier, which was great. (It depends on the ride and the restraints.) He slept all the way through a very competitive Buzz Lightyear ride in the carrier!
Columbia Harbor House is one of my favorite places to nurse. I never did on any rides (I did in some movies), but thats just because my LO wasn't a quick nurser at that time - most of the rides would have been too short (except maybe Ellen's Energy Adventure, which we skipped).
Animal Kingdom has my favorite baby care center because they have big private rooms, but they are all very nice. DHS is small, but even during busy times we never had an issue getting a nursing room or changing table.
We also recommend taking some sort of clips to clip the blanket over the stroller. We just used some binder clips that we had around.
Use baby swap and single rider lines! Sure, it means that sometimes you can't ride with your SO (we also had my parents there some of the time, so were able to go with them some), but you'll still get to ride, and often in shorter lines. We did single rider lines back-to-back, just trading off who was watching the DS one time - one time at Everest we each went about 4 or 5 times in probably 30 mins! We'd run off and swap and walk right back onto the ride - no wait!
It was way easier than I thought to take a baby to Disney. Have fun!
