You've probably noticed that VTK 6.0 does not support Qt5. However it is possible to get there if you want. You can get to the latest release from git (that, at some point will be 6.1) and you'll be able to run it with Qt5. It is easy, but as far as I know, nobody posted the exact procedure to make it even easier :P
Clone the repos:
git clone git://vtk.org/VTK.git
git clone git://vtk.org/VTKData.git
Run cmake for VTK and make sure to:
VTK_QT_VERSION to 5
CMAKE_PREFIX_PATH to the path of your Qt5 build
This is what I needed on MacOS + Qt 5.1.1.
I think I won't be different on other platforms.