Here is the summary of an update on SharePoint 2016 as published by MSDN recently.
1. Timeline : SharePoint Server 2016 will become generally be available in Q2 2016, with a public beta planned for Q4 2015.
You can request access to the public Beta program here.
2. Microsoft Confirmed to deliver On-premises releases of SharePoint for the foreseeable future. Microsoft Confirmed they will Continue to have customers who choose a combination of on-premises, cloud and hybrid deployments for many years to come. (Putting all SharePoint is dead rumors to end).
3. In SharePoint 2016, MS is paying attention to trends in content management, team collaboration and user experiences across devices.
4. Microsoft with SharePoint 2016 will also focus on how Cloud can be blended into existing on-premises scenarios in new and compelling ways. In particular, MS is focused on delivering value to customers as part of their on-premises deployments, while at the same time making it easier to take advantage of cloud innovation thru hybrid deployments of SharePoint Server with Office 365.
5. SharePoint Server 2016 will deliver enhancements and new capabilities in three major areas