This report presents key findings from the Department of Energy's Advanced Drivetrain Workshop, held on June 29-30, 2010 in Broomfield, Colorado, to assess different advanced drivetrain technologies, their relative potential to improve the state-of-the-art in wind turbine drivetrains, and the scope of research and development needed for their commercialization in wind turbine applications. The workshop featured four separate discussion tracks, each focused on a broad category of drivetrain technologies: Superconducting Drivetrains; Advanced Permanent Magnet Generators; Continuously Variable Transmissions and Fluid Drive Systems; and Innovative and Non-Traditional Drivetrain Concepts.