For those of you following development of the rviz port to Qt...
The current "unstable" release (pre-Fuerte) is now stable enough to build rviz_qt, so I have copied the rviz_qt code from visualization_experimental back over top of the rviz code in the visualization stack. I'm continuing to develop it there.
If you'd like to continue following along, abandon your old visualization_experimental checkout and look instead here:
svn co https://code.ros.org/svn/ros-pkg/stacks/visualization/trunk (for rviz)
Thanks,
Dave