From Zune Insider:

Zune will be issuing a firmware update today. There are no new features in this update, but it does address some issues we're reading about in the forums. Specifically the battery issue affecting a small percentage of Zune 30/80 GB users - I posted about this last week in case you missed it. In addition to the battery issue, this update provides some performance improvements:

  • Improved device recognition
  • Improved stability and reliability on sync (both wirelessly and while connected to a PC).

After today, your device firmware will be running 2.3. Hope everybody had a great weekend (and Monday!)

Source: Zune Insider: