This is an issue that we are addressing right now as well. In our simulation we have a block laser working to simulate the Swiss Ranger 4000, similar to the Kinect depth sensor but lower resolution. It creates a serious hit in performance in gazebo, so we are looking at getting the stereo camera gazebo plugin working again. We've found various issues in getting it to run without crashing, but still have not managed to get the valid data out of the depth buffer in orge. John Hsu has opened up a ticket with the code we've been working on at
https://code.ros.org/trac/ros-pkg/ticket/4795 Please fell free to take a look, and hopefully someone will be able to make some headway in moving this along. You can contact me if you have any questions or suggestions. We will be picking this up again in a month or so, but for now it's been put on the backburner.