TFS 2015 is now in Release Candidate (RC) and is probably Release to RTM soon. There is a lot of new stuff coming, here are some of my favorites.
The license model
There are a few rather god changes in the license model, the biggest one is that if you are an acceptance tester running test from TFS Web Access you don’t need Visual Studio Test Professional any more, you just need a TFS CAL (client access license).
Team Rooms and Chart Authoring are included in the TFS CAL.
Visual Studio Ultimate and Premium will be merged to Visual Studio Enterprise