folks,
Today I have implemented parsing, output and basic handling of uncalibrated device colors as defined in SVG Color 1.2 Working Draft: http://www.w3.org/TR/2009/WD-SVGColor12-20091001/#device
I have hooked device-cmyk handling to our color pickers so that if you select colors in the CMYK tab, these ink values will be preserved, unless you switch to some other color picker tab. Color space conversion happens every time you switch color pickers.
Both SVG 1.1 color values and device-cmyk values are output, but device-cmyk is the value used whenever it is available.
I'd like to thank the effort of the brazillian inkscape users community for mantaining a wiki-page that lists what they believe that needs to be implemented in CMYK/professional printing support from the perspective of users and print professionals. Theis wiki-page is here: http://wiki.softwarelivre.org/InkscapeBrasil/EspecificacaoCMYK (in brazillian portuguese)
Felipe "Juca" Sanches