You can check here periodically:
<http://helpx.adobe.com/lightroom/kb/tethered-camera-support-lightroom- 4.html> http://helpx.adobe.com/lightroom/kb/tethered-camera-support-lightroom- 4.html
Adobe doesn’t pre-announce support for things, and the standard answer is that they are still waiting for Canon to release their software-development-kit that supports the newer Canon cameras, so Adobe can use it to attach to them. As you can see the 1Dx shows no SDK in the Drivers and Software area:
http://www.usa.canon.com/cusa/professional/products/professional_camer as/digital_slr_cameras/eos_1d_x#DriversAndSoftware
while something like the older 5D Mark II does list an SDK being available:
http://www.usa.canon.com/cusa/professional/products/professional_camer as/digital_slr_cameras/eos_5d_mark_ii#DriversAndSoftware
Canon seems to have last released an SDK in April 2011, so any cameras newer than that aren’t supported for image capture unless they are very similar to ones that are supported and might work. The 1Dx is fairly new so wouldn’t be supported by Canon and therefore no Adobe, either, yet.
Nikon has already released their SDK for the new Nikon D800 and Capture One supports it, already, but Adobe still doesn’t so it won’t necessarily be released immediately even when Canon does release their SDK.
