Microsoft released first official theme for Windows 8 Called the Nightfall and Starlight panoramic theme.
Designed to extend seamlessly across dual monitors with identical resolution settings, this dramatic free theme for your Windows 8 Consumer Preview desktop also shifts your glass color to match each stunning, wide-angle image. Explore distant galaxies, verdant meadows, steep mountains, and serene seas without ever leaving your chair.
This theme can only be used in Windows 8 Consumer Preview or Windows Developer Preview.
Panoramic images will automatically extend across both displays of a dual-monitor setup if both monitors have the same resolution settings. If the displays are different sizes or have different resolution settings, a different image will appear in each monitor.
Panoramic themes can be used on single monitor setups, but only the center part of the image will be visible.