Today, on the SQL Server Blog, the team announced that their target date for general availability (GA) will be June 1st, 2016.
Over the past year, Microsoft has made some major enhancements to SQL Server 2016, many of which you find here in our blog. PolyBase is one of the biggest, allowing real-time, T-SQL based access to all of your data stored in Hadoop or Azure. They have completely rebuilt Reporting Services (SSRS) in the image of Power BI 2.0, and made significant upgrades to Master Data Services (MDS). A good starting point is our article on Redmond Magazine:
SQL Server 2016 Preview Reveals Path to Azure and Big Data.
You can find more detail about the pending release at Get ready, SQL Server 2016 coming on June 1st