Is this the major windows 10 update that took about an hour to install the other night?
Not likely. This is a back-port of the Windows Management Framework that came in Windows 10, and will be in Server 2016 to previous Windows versions.
It's an update for Windows 7, 8 and 8.1 and Server 2008R2, 2012, and 2012R2.
No. WMF is the backend data interface where admins and developers can access a Windows system and generate data about the installation.