Update: On Oct. 27th the article on Security fixes in Sierra 10.12.1 title revised to include the above updates - see below.
FYI on Nvidia Driver Updates: Users of Nvidia's web drivers should know that new OS X updates (versions or later build numbers after Security Updates) break the current Nvidia web graphics driver. (Some non-Mac EFI cards are not supported by default OS X drivers.) They usually appear first in Nvidia's driver prefs update check.
(Update:Video topics page has Nvidia driver updates for OS X 10.10.5, 10.11.6, & 10.12.1.)
"The macOS Sierra 10.12.1 Update improves the stability, compatibility, and security of your Mac, and is recommended for all users. This update:
- Adds automatic smart album in Photos for Depth Effect images taken on iPhone 7 Plus.
- Improves compatibility of Microsoft Office when using iCloud Desktop and Documents.
- Fixes issue that may prevent Mail from updating when using Microsoft Exchange account.
- Fixes issue that caused text to sometimes paste incorrectly if using Universal Clipboard.
- Fixes issue that may cause Mail to display unnecessary password prompts for AOL accounts.
- Improves compatibility with Fujitsu's ScanSnap scanning software.
- Addresses a "Filter Failed" error when printing to some Canon printers.
- Fixes an issue that may prevent Grapher files from opening.
- Improves reliability of Auto Unlock with Apple Watch.
- Improves security and reliability in Safari.
- Brings back Safari option to "never use font sizes smaller than" for displaying fonts on webpages.
- Improves reliability of System Image Utility and imagetool when creating network disk images."
Yamaha MusicCast Controller (US) iOS app v2.00 (iOS 9 or later)
- Improved design of Source Screen
- Compatibility with AAC format (internet radio)
- Moved Search function to browser screen of each source (Net radio, Phone/Tablet)
- Added Playlist function: Long press a song to create Playlist.
- Added Queue function: Long press a song to put it into Queue. (List in Now Playing Page)
(Ensure your MusicCast devices have the latest firmware to enable the above new features.)