The Zune team has dropped the latest software and firmware, and you can download it from zune.net, or update from within the Zune client.
Among the features of note:
- Gapless playback (yay for Pink Floyd fans everywhere!)
- Video Marketplace (get your Heroes fix on your Zune)
- Autoplaylist support
- Metadata Editing
- Windows Live Messenger integration
There's lots more, so go grab it!