As I noted and posted on another thread, if you visit the Canon USA site and click over to the 1DX page, at the bottom is the following note:
*The EOS-1D X has not been authorized as required by the rules of the Federal Communications Commission. These devices are not and may not be offered for sale or lease, or sold or leased, until authorization is obtained.
Take that for what it's worth, but until the FCC gives it an approval, it's not shipping.