Just because it isn't merged doesn't mean we can't use the feature/VS2015 branch to build some binaries.
Unfortunately it seems that there is still some issues with the static libraries, which I don't fully understand yet, especially because building the examples works flawless, but when you add SFML to VS 2015, somehow the flags don't get set right, or I don't know.
In the meantime you should probably just use the dynamic libs which worked fine for me.