No, no direct buses from DD to the theme parks. However, you can use the Contemporary bus to/from the Magic Kingdom, Boardwalk bus for Epcot/World Showcase and the Studios (transfer to boat at BW). In some cases the fastest trip can be made by just hopping on the first resort bus to come along, and changing buses at that resort (though I'd avoid AK Lodge and All-Star buses for transfers, since these resorts are off in the wrong direction from DD).