Preheat oven to 350. Grease and lightly flour 2 8" or 9" round cake pans. In a large bowl blend cake mix, eggs, oil, water and orange juice. Once blended beat on medium speed 2 full minutes. Gently fold in blueberries. Pour into pans and bake 30-35 minutes or til done. Cool on rack for 10 minutes, then invert on rack (blueberry side up) and cool completely.
For frosting: Blend butter and cream cheese till fluffy. Beat in powdered sugar and orange juice. In a separate bowl beat the whipping cream till soft peaks form. Blend whipped cream into frosting and add grated zest. Beat til combined and frost cake as you would normally frost a 2 layer cake. (Blueberry side of layers should be up)