Well, well - it seems that 2.3 software update contains more than just a few little fixes - there's some
very significant stuff in the update. I've re-published the list here for your convenience.
"Key Marketplace fixes
* Allow users to view top music videos in marketplace
* Misc improved error messaging including splitting sign-in issues into 4 separate errors for customer and support benefit
* Resolved most cases where retrieval of subscription download history stalls
* Better handling of accounts that have expired credit cards
* Podcasts with spaces in their name can now be subscribed to
* Marketplace no longer blocks explicit content purchases when parental controls are set to allow
* Points balance label is now updated when user purchases new points
Key Player UI fixes
* Allow zooming in/out (2x, 4x, fullscreen) during video playback to prevent stretched playback
* Ability to switch Zune to GDI mode through command-line parameter
Key Podcast fixes
* Allow subscriptions to podcasts larger than 10MB
* Fixed some parsing errors that prevented some podcasts from syncing to the device
* Fixed bug where podcasts were unsubscribing themselves
Key Setup fixes
* Fixed numerous bugs affecting build to build upgrades
* Improved installation for users accessing from corporate networks
* Fixed driver uninstall failures
* Included device 2.3 firmware in client download
* Failure in creating system restore point no longer blocks client installation
Key Sync fixes
* Fixed issues with reverse sync
* Fixes issues with sync meter UI showing incorrect information as to what is on the device
* Fixed issues using wireless sync with multiple devices to the same PC
* Fixed a few different issues setting up wireless sync
* Device is no longer being reported as full even after deleting large file from device
* Device content is no longer being turned into guest content when it shouldn’t be
* Content with bad metadata now shows properly so it can be removed from device
* Turning off “autolaunch when a Zune device is connected” no longer prevents “Sync Now” from working from a wirelessly connected device
* Podcast bookmarking is now transferred/saved to the device
* Wireless sync connection continues to work after rebooting host computer
* Unsubscribe podcast from device now works properly
* Changing album art in the client now updates the device as well
* Duplicate tracks are no longer synced to the device twice
Key Xbox Streaming bug fixes
* Xbox Streaming now monitors the rip folder if user changes default location
* No need to reinstall client to fix Xbox Streaming when upgrading from XP to Vista
Key Infrastructure fixes
* Vista x64 customers can now get to web help from error messages
* Client no longer crashes if database is corrupted
Key Library fixes
* Changes in pictures or video metadata made outside client will now get updated in the library
* UI is now smoother during file groveling
* When a track is added to an album we will now always update the track on disc
* User can now update album art for marketplace tracks
* 'Unknown Artist' metadata is no longer written to files when writing out user edit of album name
* Renaming an artist now more reliably keeps the change
* Two different copies of the same album no longer get duplicated down to one when it shouldn’t
* Access violation no longer occurs when checking song properties in the burn list
* Multi-disc albums imported from iTunes no longer show in the client as a single disc album
* Thumbnails for video content now extract on XP properly."
from Zune Thoughts.com