Visual Studio 2017 was launched with much fan fare yesterday (March 7, 2017). I started exploring Visual Studio 2017 from RC and I must say, after using VS 2017 I felt I was earlier leaving in stone age. It is so much better.
In short the Visual Studio 2017 is equivalent to following:
VS 2017 = VS 2015 + Loads of 3rd party plugins (like NChrunch, few ReSharper features etc.)+ Improved tooling, performance, experience, productivity etc.