I dont work for Intel, but I bought mine at the Intel IDF in San Francisco, they were telling us that they were not yet shipping to the public, but I may be wrong.....
This message was posted on behalf of Intel Corporation
Take a look at this link: https://software.intel.com/en-us/iot/hardware/joule. In this page you can check all the information available of Intel Joule, and at the beginning there is the button "Where to Buy".
I hope this link helps you.