Translucence is a new theme being developed that is based on Twentyten, the new default theme for WordPress v3x.  Translucence essentially adds the ShadowBox theme options to the Twentyten theme template files and functions.

Translucence provides options for similar “drop shadow” borders that is the central design motif of ShadowBox as well as options for setting the color and opacity of various areas of a site including the header, footer, sidebars and content.  For more information, see:
http://segueproject.org/themes-translucence

ShadowBox is a theme I am developing for a number of platforms including WordPress, Moodle, MediaWiki and Segue.  The design metaphor of ShadowBox is quite simple, that of a rectangle in the foreground that casts a shadow on the background.

Central to the design of ShadowBox and other themes that share its design approach, is variations.  Variations are different versions of the theme using the same template files.