They are really speeding up at the TFS team. The TFS 2018 RC1 is out and its a go-live, meningen there are full support for production.
There will be major changes like deprecation of XAML build, Sharepoint integration and MTLM
Some of the new features are Maven Package support, Wiki support, New Release management layout, Git forks and so on.
Read the full info here: TFS2018RC1