XEEN Cine lenses are 6K compatible with future Sony 6K cameras.

New 24mm XEEN on the new Sony A7rII (Image courtesy: DSLRmagazine)

As you know recently Samyang/Rokinon launched the new XEEN Cine lens line. Those lenses are much cheaper than other current Cine lenses from Zeiss and Schneider. Full specs and preorder are available at BHphoto:
Rokinon Xeen 24mm T1.5 Lens (Click here).
Rokinon Xeen 50mm T1.5 Lens (Click here).
Rokinon Xeen 85mm T1.5 Lens (Click here).

DSLRmagazine (google translation here) tested the lenses on the A7rII and added an interesting note. He got informed by Samyang that those lenses are not only superb for 4K recording but they are also 6K ready if Sony or other camera manufacturer will launch those kind of cameras in the near future.

Newsshooter tested those lenses on the Sony A7rII to see if they can come close to the Zeiss-Schneider quality:

In the test the XEEN lens appeared to be warmer than the Sony or Zeiss. In 4K the XEEN also appeared to be the sharpest of the three. The Sony had a nice image and bokeh was quite pleasant, but there was a slightly strange rendition of the light on the phone. To my eye the Zeiss did look more cinematic, but you may have a different opinion. The Zeiss was also the only lens to exhibit obvious lens flares.

XEEN 85mm T1.5 vs ZEISS CP.2 85mm T1.5 vs Sony CineAlta 85mm T2.0 with Sony a7R II. Ungraded

There is also a first impression review at BH Explora (Click here):

I found the Rokinon XEEN Cine Lenses to be well made, easy to work with, and overall I enjoyed the image quality. They rendered naturalistic images with good contrast and a pleasing, slightly warm feel. Intercutting between the lenses required no additional color correction beyond applying the same LUT to the footage. It is my preference to shoot more closed down than wide open, and I did feel the lenses performed best starting around T4, but I was still satisfied with footage shot at T1.5. Overall, I was pleased with the XEEN lenses and look forward to working with them again.

Full specs and preorder are available at BHphoto:
Rokinon Xeen 24mm T1.5 Lens (Click here).
Rokinon Xeen 50mm T1.5 Lens (Click here).
Rokinon Xeen 85mm T1.5 Lens (Click here).