I don't know what you mean in your instructions: "Do not forget to configure (windows->preferences->arduino) or nothing will work. "
@scottGV2 does not work "out of the box" with Arduino 1.0.4. If you copy platform.txt next to boards.txt it might work but I never tried.Can you share your experiences in getting this to work?
The problem you have is with CDT and not with the arduino eclipse plugin.I think you installed juno and added CDT later. Apparently the C/C++ editor is not properly installed.Best regardsJantje