Thank you for interest in the Intel® Joule™ Products.
We don't have a specific date of release for the Joule Expansion Board Design Guide, so I can't answer your question. We hope to release it soon, so please be aware in the community and the updates about the Intel Joule Platform.
Intel recently made this documents public, I think you will find them useful:
Joule Expansion board design guide, http://www.intel.com/content/www/us/en/support/boards-and-kits/intel-joule-kits/000023390.html http://www.intel.com/content/www/us/en/support/boards-and-kits/intel-joule-kits/000023390.htmlhttp:/...
Expansion board design guide, http://www.intel.com/content/www/us/en/support/boards-and-kits/intel-joule-kits/000023394.html http://www.intel.com/content/www/us/en/support/boards-and-kits/intel-joule-kits/000023394.html