With the release of the new zunes came the release also of the new software, along with it's new colors and interface. However, as crappy as the old software may be, some do find the color scheme of the v1 software nice...
WillysJeepMan, member of Zunerama forums has made a simple point-and-click tool will modify your Zune Software to look like the old-school we used to love/hate.
Download it here: ZSM-DarkTheme (follow the README file)
[via Zunerama Forums]