It looks like the primary change is compatibility with the new Z-mount DX lenses, with optical VR, mainly intended for the new Z50. But that is still a bit of a priority. So far no Z-mount FX lens has optical VR.

There are a bunch of other changes, but compatibility with CFexpress cards is not included. That will have to be another firmware update. My guess is that Nikon is still testing with various CFx manufacturers, and those cards are also not yet available.

The following change list is directly from Nikon’s web site:

Added supported for optical VR with NIKKOR Z DX 16–50mm f/3.5–6.3 VR and NIKKOR Z DX 50–250mm f/4.5–6.3 VR Z-mount lenses. Note that attaching these lenses disables the Mechanical shutter option for Custom Setting d5 (Shutter type) in Group d (Shooting/display) of the CUSTOM SETTING MENU, leaving a choice of Autoand Electronic front-curtain shutter options only.

  • ISO sensitivity can now be adjusted using the lens control ring, and ISO sensitivity has been added to the options available for Custom Setting f2 (Custom control assignment) > Lens control ring in Group f (Controls) of the CUSTOM SETTING MENU.
  • As of November 14, 2019, the aperture display in the lens info panel for NIKKOR Z 24–70mm f/2.8 S and NIKKOR Z 58mm f/0.95 S Noct lenses shows both the current aperture and adjacent aperture values in modes A and M.
  • When On was selected for Auto ISO sensitivity control and an option that does not include “slow sync” was selected for Flash mode, shutter speed was formerly restricted to values between those chosen for Custom Settings e1 (Flash sync speed) and e2 (Flash shutter speed), but this has now been changed to match the behavior of digital SLR cameras, with the result that the minimum shutter speed now corresponds to the value selected for Auto ISO sensitivity control > Minimum shutter speed.
  • Fixed an issue that in extremely rare cases resulted in the camera failing to correctly record movies with 1920×1080; 120p selected for Frame size/frame rate.
  • Fixed an issue that occasionally resulted in “noise” in the form of white lines at the bottom of the display when the electronic viewfinder was on.
  • Fixed an issue that in rare cases resulted in “noise” in the form of fine horizontal lines appearing throughout the frame in movies and the live view display.
  • Fixed errors in the UTC time zones for the following three cities in the Time zone and date > Time zone display in the SETUP MENU:
    • Caracas: was -4:30, is now -4:00
    • Casablanca: was 00:00, is now +1:00
    • Ankara: was +2:00, is now +3:00
  • Fixed an issue that resulted in an incorrect date of creation being displayed in the Windows 10 “properties” dialogs for movies and time-lapse movies created with the camera, as well as copies created with camera movie editing controls.

Downloads:
Nikon Z6: Download Firmware v2.10 – Z6
Nikon Z7: Download Firmware v2.10 – Z7