In 6-quart Dutch oven, heat sugar, milk, butter and cream cheese to boiling over medium-high heat. Cook 6 to 8 minutes, stirring constantly. Reduce heat to medium. Cook about 10 minutes, stirring occasionally, to 225°F on candy thermometer; remove from heat. Quickly stir in marshmallow creme and vanilla. Pour 4 cups hot marshmallow mixture over white chips in bowl; stir to mix. Into remaining marshmallow mixture, stir milk chocolate chips, semisweet chocolate chips, cocoa and nuts.