The GFX100 is equipped with in-body stabilization that adds up to 5.5 extra stops of shake reduction. It's also got 30 fps 4K video with 4:2:2 10-bit recording capability, another first for a medium format camera. That should make for incredibly shallow depth-of-field, and Fujifilm has promised "wide tonal reproducibility and extra high ISO sensitivity, producing high quality video footage with detailed textures." Given the resolution, it likely does some line skipping, so video might get some aliasing and moire, however.
Other features include a tilting rear touch display, 5.76 million dot interchangeable EVF, dual UHS-II card slots and dual batteries. The focal plane shutter has springs to reduce shutter shock that can result in blurry images.
You'll be able to capture 16-bit RAW images, making it easy to draw detail out of shadows and highlights. All of Fujifilm's usual filters, like Velvia, Eterna Cinema and Monochrome are available.The GFX100 also has a new "Smooth Skin Effect" function to flatter your portrait subjects without the need for any post-processing.
The GFX100 is weather sealed "to ensure an exceptionally high level of dust and moisture resistance," Fujifilm said. While it's obviously not small, it's about the size of a full-frame DSLR and weighs about 3 pounds including two batteries, a memory card and the EVF.
You're probably now bracing for the price, and rightfully so, as the Fujifilm GFX100 costs $10,000 without a lens. That's actually reasonable for what it is -- for instance, Hasselblad's X1D costs $8,500 but has less than half the resolution. The GFX100 goes on sale starting June 27th.