I have been thinking about the same thing, as we are going in early December. Last year, before a trip to Europe, I found a pair of shoes in Kmart called "Safetrax." They are made for people who work on their feet all day, like factory workers and wait staff. They are very plain black, slip-on loafers, with stretchy fabric where the top meets the sides so they are no problem to slip on. They have a rubber sole, and I think they look great with jeans. (I am not able to pull off jeans and running shoes, I have short legs and this makes them look even stumpier.)
I wore the Safetrax for two straight weeks, every day, walking around five cities in Europe, on cobblestone streets, on trains, trolleys, etc. I had absolutely no problems, and my husband wore New Balance and complained every night. Plus, I know they are water resistant after a few rain showers caught us.
Now I will say, we were in some colder climates, and I wore them with nice thick wool socks most days, but also with thinner trouser socks, which I would probably do in WDW. But the wool socks wicked away all perspiration and worked great. My feet were nice and warm. But I can see how these won't be everyone's cup of tea, especially if you are used to sandals at the parks. They just work so well for me, and my feet are always cold.