Some of the interesting tidbits:
– A7s has been developed along the A7 and A7r cameras
– development took 2-3 years
– Reason why the camera doesn’t record 4K internally is because of power consumption and because of the heating produced by the large sensor
– The one big physical change compared ot th A7-A7r is that the A7s has a stainless steel made mount.
Newsshooter is busy producing videos (by the way great work guys!). And here is the a video about the new Atomos Shogun 4K recorder for Sony a7S: