Petapixel did an interview on the CP+ with Sigma. There are good news and bad news.
First the bad news. We probably have to wait for at least another 3 years until a Sigma cameras with Foveon sensor can be produced in masses. Reasons in detail here (see also the PetaPixel Podcast for this):
petapixel.com
That is a pitty. I am a big fan of the Foveon sensor. Depending on how the sensors will be in 3 years, there might not be an argument anymore for a Foveon sensor, expecially if it will costs significantly more than "normal" sensors.
The good news is, that Sigma seems to have now the capacity, to develop and produce even more new lenses for the L-Mount and is even thinking about producing lenses for Medium Format. See here and the Podcast:
petapixel.com
As you might know, Zeiss does not make lenses anymore for normal cameras. Contax does not exist anymore and the cooperation with Sony and Fuji fall asleep afaik.
According to the Podcast of PetaPixel, Sigma wants to become the new Zeiss. As we can see with their L-Mount Art and other lenses, they achieved it. Sigma is in my view the main driver for the lens-line up in L-Mount. 41 out of 80 lenses are from Sigma.
Beside the Lumix S5, the Sigma lenses, especially the i-series lens line, have been the ones which convinced me to invest into the L-Mount system.
First the bad news. We probably have to wait for at least another 3 years until a Sigma cameras with Foveon sensor can be produced in masses. Reasons in detail here (see also the PetaPixel Podcast for this):

Sigma's Full-Frame Foveon Camera is Still at Least 'a Few Years Away'
It is not guaranteed it will arrive at all, but Sigma is dedicated to working on it anyway.
That is a pitty. I am a big fan of the Foveon sensor. Depending on how the sensors will be in 3 years, there might not be an argument anymore for a Foveon sensor, expecially if it will costs significantly more than "normal" sensors.
The good news is, that Sigma seems to have now the capacity, to develop and produce even more new lenses for the L-Mount and is even thinking about producing lenses for Medium Format. See here and the Podcast:

Sigma's CEO Wants to Make Lenses for Medium Format Cameras
Sigma has the ability and time to devote to medium format support now.
As you might know, Zeiss does not make lenses anymore for normal cameras. Contax does not exist anymore and the cooperation with Sony and Fuji fall asleep afaik.
According to the Podcast of PetaPixel, Sigma wants to become the new Zeiss. As we can see with their L-Mount Art and other lenses, they achieved it. Sigma is in my view the main driver for the lens-line up in L-Mount. 41 out of 80 lenses are from Sigma.
Beside the Lumix S5, the Sigma lenses, especially the i-series lens line, have been the ones which convinced me to invest into the L-Mount system.