I pretty much come from the camp of if it ain't broke, don't fix it. Or, at least, don't fix it right away until everyone else experiences all the bugs and problems :)
That being said, there is a new Zune 2.5 Software Update that you can download now.
As far as what appears to be new:
“We've updated the Zune software with features our community's been asking for, including gapless playback, smart playlists, new sorting options, multiple-device syncing, and advanced song info editing, including drag-and-drop functionality. If you have Windows Live Messenger running, it'll let your contacts know what you're playing. And when you go to Zune Marketplace, you'll now find over 800 episodes of popular TV shows to download, plus more than two million DRM-free MP3s.
Great news for members of the Zune Social: the discovery experience is now fully integrated into this update. Send messages and listening recommendations directly from the software. Zune Pass subscribers: sync your friends' Zune Cards with your device and their music comes along—their recent plays, favorite tracks, and top songs from their most-played artists[3]. Even if you don't have a Zune Pass, you'll still see their play data on your device, so you can choose what you want and buy the songs next time you sync.“
Download it here.
If you want to develop games for Windows, Zune, and the XBOX 360, download the latest XNA Game Developer Studio 3.0 CTP.
Per the download description:
“This release represents the Community Technology Preview of Microsoft XNA Game Studio 3.0, which enables hobbyists, academics, and independent game developers to easily create video games for Windows and the Microsoft Zune digital media player using optimized cross-platform gaming libraries based on .NET.
Targeting the Xbox 360 console is not supported in this CTP release. It will be supported in the final release version.
This CTP release of the 3.0 version contains support for the Visual Studio 2008 family of products and for developing games that run on the Microsoft Zune digital media player. In addition, there are enhancements to the XNA Framework API for media support and sound effects.”
Download it here.