The big deal about the camera they're hyping is that it's packing essentially the same sensor as the eye-bleedingly expensive GFX100 at sixty percent of the price.
Medium format sensors are, these days, where Full Frame ones were about fifteen years ago. After all, the EOS 1Ds Mark II, when it came out back in 2004, stickered for eight grand. Canon's first enthusiast/prosumer full-frame body, the 5D, was nearly $3500 in late 2005.
There's a reason that for a long time, people referred to Full Frame cameras as the digital equivalent of Medium Format. Now that Full Frame is common and can be had for a thousand bucks or a little less, actual digital Medium Format is the digital equivalent of Medium Format.
Funnily enough, while we've seen the prices of large sensors drop precipitously over the last decade mostly due to economies of scale, that's likely to change in the future as the demand for dedicated cameras drops off sharply.
"To some degree, the image sensor is dictating things. On the old 8" wafers used to make sensors, the best possible case was going to always say that a full frame sensor would be 4x to 5x the cost of an APS-C sensor. That APS-C sensor was about the largest size you could make without making multiple passes for each layer of the sensor, so full frame sensors took longer on the fab and had more things that go wrong with them. Moreover, the yield goes down with full frame for multiple other reasons, including wasted space on the wafer. For a while, sensor prices were going down. These days, due to low volume, they're going back up."
