For those interested in the insides of DNG Camera profiles, and how to edit them, I've written dcpTool.
dcpTool is a compiler/decompiler for DNG camera profiles (.dcp files). dcpTool can decompile binary format DCP files into an XML format for editing with a text editor or whatever, and then compile the XML format file back into a binary DCP file, as well as extract embedded profiles from DNG files. It runs on Windows and OS X command lines, and is based on V1.2 of the DNG SDK.
See here: http://dcptool.sourceforge.net/
Health warning: dcpTool is a command line utility - if you're not comfortable with command line stuff, dcpTool probably won't be of any interest to you.