This release is the first in the following ways:
1.First release of SSDT that includes all the BI tools like IS, AS, RS (AS/RS will come later)
2.First release of IS designer public preview for sql server 2016.
3.First release of IS designer that is independent from AS/RS installation.
4.First lighter weight installer instead of SQL server installer is used.
This dramatically simplifies how users install and update their SQL Server tool inside Visual Studio.
You can download the bits from below links, Enjoy!