Microfeature workpieces having interconnects and conductive backplanes and associated systems and methods are disclosed herein. One such device includes a semiconductor substrate having integrated circuitry and terminals electrically coupled to the integrated circuitry. The device also includes electrically conductive interconnects extending through at least a portion of the semiconductor substrate and electrically coupled to corresponding terminals. The device further includes a conductive backplane assembly having a conductive layer at a back side of the semiconductor substrate. One or more of the interconnects are electrically coupled to the conductive layer at the back side of the semiconductor substrate.