The Mileura Widefield Array (MWA) is a proposed US-Australian observatory located at the radio quiet Mileura Station in Western Australia. The MWA is optimized for widefield observations and survey science, including the Epoch of Reionization (EOR), Heliospheric Science, Radio Transients, Pulsars, and HI surveys. The astrophysics reach of the MWA, ranging from experimental cosmology to solar magnetic field structure to the dynamic radio sky, illustrates the science potential of wide field observatories. In this talk I will detail the unique design of the MWA and introduce the cosmology and radio transient observations it enables.