SharePoint team has just anounced SharePoint Server 2016 Beta 2 and Project Server 2016 Beta 2!
This is the last public preview of SharePoint Server 2016 before General Availability which is expecting to be in Q1 of 2016. Upgrade from SP Server 2016 IT Preview is not supported and you need to install beta 2 and migrate IT Preview content to the new Beta 2 deployment.
Some links:
Announcing SharePoint Server 2016 Beta 2 and Project Server 2016 Beta 2
SharePoint Server 2016 Beta 2 (download link)
SharePoint Server 2016 Beta 2 (technet resources)
If you stumbled into some issues with this beta, you can find help on this forum: SharePoint Server 2016 Preview (Technet forums)
