Manoj Pandey tells us that SQL Server 2016 CTP 3.1 is now available:
–> Following are enhancements in some areas:
1. New In-Memory OLTP improvements, including Unique indexes, LOB data types, and Indexes with NULLable key columns.
2. The COMPRESS and DECOMPRESS functions convert values into and out of the GZIP algorithm.
The list goes on, but item #1 is intriguing.