Melt 2 tablespoons butter in large skillet over medium heat. Add onions and sauté until brown, about 15 minutes. Set aside.
Bring 4 1/2 cups broth and 1 tablespoon thyme to boil in large saucepan. Add wild rice; bring to boil. Reduce heat; cover and simmer 30 minutes. Add white rice; cover and simmer until all rice is tender and liquid is almost absorbed, about 15 minutes longer.
Stir dried apricots, dried cherries, raisins and 2 tablespoons thyme into rice mixture; cover and simmer 3 minutes. Stir pearl onions and remaining 4 tablespoons butter into rice. Mix in pecans. Season generously with salt and pepper.
To bake stuffing in turkey:
Loosely fill main cavity with cool stuffing. Butter glass baking dish. Spoon remaining stuffing into prepared dish. Cover with buttered foil, buttered side down. Bake stuffing in dish alongside turkey until heated through, about 20 minutes.
To bake all of stuffing in baking dish:
Preheat oven to 350°F. Butter 13 x 9 x 2-inch glass baking dish. Transfer stuffing to prepared dish. Cover with buttered foil, buttered side down, and bake until heated through, about 30 minutes.