Jani Heikkinen today announced the first Qt 5.9 Alpha snapshot. This isn't the formal Qt 5.9 Alpha release, but will become the official Alpha source package if there isn't anything important that's missing. Hit up that mailing list link if you are interested in testing.
Among the changes coming for Qt 5.9 is a new qfloat16 class in Qt Core, QPainter's OpenGL engine now works with core profile OpenGL contexts, compute shaders are now supported in QOpenGLShader and QOpenGLShaderProgram, Qt Quick has its own on-disk shader program binary cache, an OpenVG back-end was added to Qt Quick, multi-touch support was added to Qt Quick Controls 2, Qt WebEngine was upgraded, Qt Location has a number of map-related improvements, Qt 3D's new animation subsystem is in technical preview form, the Qt Virtual Keyboard has been improved, experimental DRM dumb buffer support, and new modules. Qt 5.9 is shaping up to be a heck of a feature-packed release.
One of the new modules is Qt Gamepad and is for exposing gamepad controller input to C++/QML applications. Technical preview modules for Qt 5.9 include Qt Remote Objects, Qt Network Authentication, and Qt Speech. The two latter modules are up to their second tech preview phase. Qt Script meanwhile has been deprecated in Qt 5.9. More Qt 5.9 feature details via the Wiki.
The Qt 5.9 formal alpha release is expected 1 March, the beta release is expected 5 April, and The Qt Company is hoping to see the official Qt 5.9.0 debut on 31 May.