Video resolution/framerates. The highest video rates are still 4K60 and 1080p240, the same as the HERO7 Black, but the maximum bitrate has been bumped up to 100Mb/s.
New Mod Accessories. There are three new dedicated accessories, or Mods: an external mic, a flip-up display, and an attached light. The accessories are coming later–they're expected to be available for preorder in December.
Improved in-camera processing. Improvements to in-camera processing, with upgraded versions of HyperSmooth video stabilization, TimeWarp, and SuperPhoto.
New LiveBurst feature. There's a new LiveBurst feature that pre-rolls still burst mode photos. It starts shooting 1.5 seconds before you press the shutter and then gives you a burst of 90 images to choose from.
Night Lapse Video added. It also has Night Lapse Video, so you can use the extended shutter times with a time lapse compiled in-camera now rather than having to compile the images to video afterwards. In previous models, only Night Lapse Photo was available.
Built-in mount point on the bottom of the camera. There's a new built-in mounting point that folds away into the base of the camera, so you won't need to use the frame housing to mount the camera.
Live streaming in 1080p.
Some usability improvements such as custom presets (one of the features I suspected they might add after DJI did it on the Osmo Action) and quicker FOV switching now called digital lenses.
The RAW photo format is now available in all photo modes rather than just some.