From Sigma:
Sigma 500mm f/4 DG OS HSM Sports Firmware v.1.01:
* For this update, it requires the firmware of the SIGMA USB DOCK for NIKON to be Ver.1.01 or later.
* Before updating the firmware of the 500mm F4 DG OS HSM | Sports for NIKON, Please ensure SIGMA Optimization Pro has been updated to Ver1.4.1 or later for Windows, or Ver1.4.0 or later for Macintosh.
B&H carries the Sigma 500mm f/4 DG OS HSM Sports Lens and USB Dock and has the Sigma 100-400mm f/5-6.3 DG OS HSM Contemporary Lens available for preorder.