Specifications for the upcoming mobile version of NVIDIA's GTX 1070 GPU may have leaked, and according to the report at VideoCardz.com this GTX 1070M will have 2048 CUDA cores; 128 more than the desktop version's 1920 cores.
The report comes via BenchLife, with the screenshot of GPU-Z showing the higher CUDA core count (though VideoCardz mentions the TMU count should be 128). The memory interface remains at 256-bit for the mobile version, with 8GB of GDDR5.
VideoCardz reported another GPU-Z screenshot (via PurePC) of the mobile GTX 1060, which appears to offer the same specs of the desktop version, at a slightly lower clock speed.
Finally, this chart was provided for reference:
Image credit: VideoCardz
Note the absence of information about a mobile variant of the GTX 1080, details of which are still unknown (for now).