Great! I tried that change of the Descriptor to 0 in "\arduino-1.5.1r2\hardware\arduino\sam\cores\arduino\USB\USBCore.cpp" and tested the KeyboardAndMouseControl example sketch and it worked correctly. (Note: I needed to delete the existing driver and let it reinstall to get the composite USB be recognized)
The question is, I double checked the "\arduino-1.0.2\hardware\arduino\cores\arduino\USBCore.cpp" file for the Leonardo and Micro, but they have the same class 2 definition if CDC_ENABLED? So what is different here that makes it work?