Looks like someone sneaked in a video camera in to record the demo of the Zune HD at the GDGT Party (see Video 1). The device looks really nice and they elude to really long battery life on the device. Which is some what expected as the Tegra hardware platform is meant to be able to play audio for 24 days… yes days not a typo (see Video 2).
Video 1. Zune HD Demo – Spy Video
Video 2. Tegra – Days of Battery Life