Now this is all still Inkscape-level stuff, but once we get a bit further we plan to contribute the core parts of the CSS design back to the Tango project.
Tango is a project to develop a common style that could be used across GNOME and KDE desktops. The idea is that using the shared outlook applications between different systems (and third-party applications that don’t originate from either desktop environment) would fit together quite seamlessly. With Freedesktop handling much of the technical interoperability, Tango could solve the UI consistency.
The same could be done between the different Open Source CMS systems and web tools. Tango could easily be something for OSCOM to push as an interop project.