Yesterday Microsoft released the Technical Preview 5 of Windows Server 2016. They say that this will be the last TP they will release for 2016 and that no extra featues will be present in the final release but they may be improved still.
The flavours of the OS remain the same in this release also. We have the GUI edition, server core and of course nano server. Nano server is offered on the ISO file as a .wim image which can be customized with the tools included on the ISO and can be obtained also as a separate VHD image which can be attached to a virtual machine and run.
You can download the OS images from the following link: Download Widows Server 2016 Technical Preview 5.
While no big features are new in this release, there are a lot of improvements. Read everything new from this link: What’s new in Windows Server 2016 Technical Preview 5.