There have been no announcements made on making Kinect for Windows v2 available on Windows 7. If there are any changes made to support for operating systems, that will be provided on the main website.
http://www.kinectforwindows.com
Windows 7 does not natively support USB3 at the operating system level. There was significant work done to Windows 8 to natively support USB3 to ensure compliance with the official specification.
Carmine Sirignano - MSFT