Starting from now on I will blog about new features in Windows Server 2016.
The first one is about new feature in Hyper-V - starting from Windows Server 2016 (and also Windows 10 v1607) you can add or remove memory for guest virtual machine while it is runnning. If you do this, actual memory amount in guest VM Task Manager will also change.
The requirement for guest OS is Windows 10 or Windows Server 2016. And this feature works both for Generation 1 and Genereation 2 virtual machines.