Many people are asking, "why so many updates and Previews for the next Configmgr release"
Well you have to understand the speed at which Microsoft is now moving. Look at the updates made to Intune and the new Windows Servicing Model.
In line with that change we have a the more Windows 10 management coming to the next update, Windows 10 Services.
More information can be found here:
http://blogs.technet.com/b/configmgrteam/archive/2015/10/14/now-available-october-update-for-system-center-configuration-manager-tp3-.aspx
Windows 10 Servicing works of a what is referred to as "branches" These branches determine how fast the update is applied to your machine. Branches are NOT security or stability updates, these come to all machines. The branches are the features or a major jump in the OS. Like a 10.1 to 10.2.
This will allow you to see what branch is running and the progress.
I think a good article about the branches and servicing can be found here: http://www.thewindowsclub.com/windows-10-servicing-branches
A link to the TechNet article can be found in the Team blog mentioned above.
Why do we need to be concerned with Servicing with ConfigMgr?
Well put simply, you need to know what you have in your environment so you can properly prepare the machines and keep them moving forward.
Do you have an MRI machine running from a Windows 10 device. These devices are typically kept in a steady state and don't want much change per the manufacture of the external devices. For this reason you would use the LTSB Long Term Servicing Branch because you don't want OS change every few months. This change in years. No exact length is known because Microsoft is now just releasing 10. But this allows these special machines to be maintained without much change.
What is cool about this update is that it uses the "Updates and Servicing" node in the Preview.
Please remember to add your "voice" to the changes and features via the User Voice feed back page:
http://configurationmanager.uservoice.com/forums/300492-ideas