Yep - haven't done Disney yet as gluten free.
Gluten free is relatively easy. Avoid soups, which often contain flour as a thickener. Avoid fried foods that are often dredged in flour. Mention it to your waitstaff. Also, I think it depends how gluten free you need to be - I get uncomfortably gassy and crampy, but it wouldn't ruin my trip (maybe my evening). Other people can't tolerate any gluten at all without much more severe consequences. That's harder to do. (I sometimes decide to take the consequences for a taste of something).
At Disney, call ahead. They have enough gluten free guests that they generally do something specific if you have a specialized diet.