The Open Hardware Definition has been updated with a statement of principals:
Open source hardware is hardware whose design is made publicly available so that anyone can study, modify, distribute, make and sell the design or hardware based on that design. The hardware's source, the design from which it is made, is available in the preferred format for making modifications to it. Ideally, open source hardware uses readily-available components and materials, standard processes, open infrastructure, unrestricted content, and open-source design tools to maximize the ability of individuals to make and use hardware. Open source hardware gives people the freedom to control their technology while sharing knowledge and encouraging commerce through the open exchange of designs.
Please view the entire definition draft here. And we invite you to post your thoughts, changes and addition to the definition on the forums for the 1.0 version. There will also be continued discussions on the mailing list. Special thanks to everyone who gave feedback for the 0.4 draft, especially Windell Oskay, David Mellis, and Phillip Torrone for their hard work dedicating much time on the wording. Read another excellent post on the topic by Sparkfun.