Qt3D is the Qt component that adds 3D support to Qt Quick for easily integrating 3D functionality. Qt3D has been in development for some time and was going to be an "essential" module to Qt 5.0 before being moved to just an add-on as part of Nokia's Qt changes prior to selling it to Digia. Qt3D offers up a lot of potential for 3D user-interfaces and applications, but hasn't seen too much work recently -- the last time we got to mention it was when talking about OpenGL taking on a greater role within Qt in late 2012.
Fortunately, Qt3D is back to being workedo n and Sean Harmer at KDAB shared some of what's being done. The front-end will be accessible via QML or C++, is being designed for flexibility and ease of future development, should be easy to add other components and aspects/systems later on, and various other items are being talked about. See this mailing list post for more details.
QtOpenCL is also being talked about once again. QtOpenCL is a Qt-style wrapper over OpenCL that was in development during Qt4 but its adoption really didn't take off either. Last year we talked about QtOpenCL potentially being picked up again, but only now does it seem that renewed interest is building for a Qt way to take advantage of GPGPU compute support. This weekend a developer started bringing QtOpenCL to Qt5 via this Git repository and is talking about possibly wanting QtOpenCL to become a Qt Labs project.