A connector arrangement for a wall panel system is provided which includes connector blocks that join serially-adjacent wall panel frames together in proper alignment with each other. These corner blocks also are matable with a system of spacer strips, light block strips, single-side trim covers and multi-side trim covers which enclose the connector blocks and connector structure. A corner spline arrangement is also provided between adjacent trim covers which spline extends vertically and defines a closed corner, right-angled corner between the interconnected trim covers.