We just got back from a short trip with our 9 month old (you can see my trip report on the TR board, and restaurant reviews on the R board). DH and I have been there together once, but never with a baby. We had an absolutely wonderful time. I know so many people said "isn't she too young?" or "she won't remember it". So what! I have tons of pictures and video, and DH and I have memories to last our lifetime and hers! So don't let anyone discourage you.
My DD is on formula. I bought a powdered milk container which I thought was a great idea. You might want to try that, got it at One Step Ahead's website. But we ended up using ready-made formula that came in small 8oz. cans, so we didn't have to drag a cooler or worry about it spoiling. It worked out wonderfully. I would strongly recommend taking advantage of the Baby Care Stations. The CM's are wonderful there, and there were like 5 changing tables, room for baby to crawl, and highchairs for feedings. We visited these several times at the parks, and to us it was not too much of a hassle.
As for the rides, I think you are able to carry the baby onto rides that have no height requirement. However, we only rode Haunted Mansion, Pirates, and Small World. DD was a little scared at first on HM and Pirates, but she just held onto me or her daddy tight. She didn't cry. I don't know how your baby might react. She loved Small World. We only did the Baby Swap once, on Space Mountain.
They are good about providing high chairs at all the restaurants we visited. We stayed at the CR for one night, and provided us with a crib which was fine.
I especially loved my Stroller tote, which I also bought from One Step Ahead. It attaches to the handlebar, so no fussing with digging a bag out of the stroller. We also brought our own stroller, which reclined all the way down. Perfect for baby taking naps and she slept well in it. I also had a Baby Bjorn, for when she got fussy in the stroller. DH and I loved that. We stopped frequently to take breaks and give her water because it was so hot.
I just recommend you take your time, go with a pace the baby is comfortable with and enjoy your trip! We didn't get to do all the things we usually do but we had time to stop and smell the roses. IT was relaxing, and definitely a wonderful experience taking our daughter to WDW. I"m sure you'll have a great time.