I assume you mean as an official build provided on the Qt Project web site. It will take someone to set up the whole CI infrastructure and then they can work on fixing the inevitable minor build glitches. Don't expect it one week after the compiler was released. You could ask on the dev mailing list.
http://lists.qt-project.org/pipermai...ly/022225.html

In the meantime... If you want to build Qt with VS 2015 then you have the source.