I've been developing for NRefactory several years now after the roslyn release I made a new 6.0 version. For the 6.0 version there are bad and good news.
The bad news is that it's no longer in development.
The good news is that the successor of the refactoring part is (RefactoringEssentials). The rest of the code has been moved to the monodevelop source code and is still available and in active development as open source.
So the 5.0 version will remain - and will be still maintained a bit by Daniel Grundwald and me.
Why was this decision made ?
Mostly because most NRefactory6 code was just wrappers around internal roslyn classes (and making them public). I don't think that it's worth as a stand alone library.
Since #Develop was discontinued the 2nd big NRefactory user is no longer around and it's more time effective to move that code to monodevelop and split the refactorings so they can be used in VS.NET 2015 as well.
So I deleted the NRefactory6 today. Bye NRefactory we had a nice time - and hello RefactoringEssentials :)