Microelectronic devices and methods for filling vias and forming conductive interconnects in microfeature workpieces and dies are disclosed herein. In one embodiment, a method includes providing a microfeature workpiece having a plurality of dies and at least one passage extending through the microfeature workpiece from a first side of the microfeature workpiece to an opposite second side of the microfeature workpiece. The method can further include forming a conductive plug in the passage adjacent to the first side of the microelectronic workpiece, and depositing conductive material in the passage to at least generally fill the passage from the conductive plug to the second side of the microelectronic workpiece.