Preheat the oven to 400 degrees F.
Pierce the potatoes all over with a fork. Place on the oven rack and bake until fork-tender, about 45 minutes. Let cool slightly and cut each potato in half lengthwise. Scoop out the pulp, leaving a 1/4-inch layer in each shell. Transfer the pulp to a medium bowl and mash with a potato masher. Add the goat cheese, milk, olives, olive oil and salt until well mixed.
Mound the filling into each potato half and transfer to a baking sheet. Bake until the filling is hot in the center and the edges are lightly browned, about 10 minutes. Top each half with the dill and sprinkle with the pine nuts.