Usually, when Apple updates OS X, it includes updates for Boot Camp, which is part of OS X. Make sure you have a good backup or clone of both your OS X partition and your Boot Camp partition. Of course nothing is perfect, so issues may arise.

The only present version of macOS Sierra right now is a beta version.

Not sure what kinds of drivers are expected to be included there; so

it may be wise to avoid experimentation with your only working Mac.

• Get ready for macOS Sierra - Official Apple Support

A partition is advised if your Mac has large enough drive with plenty

of unused empty capacity; yet, a partition may compromise the Mac.

At some point there should be BC drivers for a later official release 10.12.

Good luck & happy computing!

FWIW, You may be "jumping the gun". There is no indication MacOS Sierra will be released today.

This fall (a few weeks away?) the release candidates should be finalized

and those versions available for the general public; as suggested today:

Apple releases iOS 10, macOS Sierra, watchOS 3 and tvOS 10 GM seeds, Sierra to launch Sept. 20

-- according to an official Apple report, (Sierra, set to launch Sept 20) noted on 'appleinsider'

Hopefully you aren't failing to backup your present system, plus make

yet another backup, separate from the first; before attempt an upgrade.

Good luck & happy trails!