Tried it, still didn't work. Running Windows 7 x64. These are my file contents:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Freescale\Freescale MQX\4.0 CAM_DBU_K60F120M]
"INSTALL_DATE"="03-10-2013"
"PACKAGE_DATE"="2013/10/03"
"PACKAGE_SIZE"="0"
"PATH"="C:\\Freescale\\mqx_4.0"
"VERSION"="4.0.2"
I shut down CW 10.5, put cam_dbu_k60f120m.xml in C:\Freescale\CW_MCU_v10.5\MCU\lib\wizard_data\mqx\4.0\arm, executed cam_dbu_k60f120m_x64.reg (my hack of the original .reg file), restarted CW, and tried creating a new project... the same board families were listed (CF, CF+, and Kinetis eval boards), no listing for my custom board.
There's got to be a better way to do this. This functionality should be integrated into the BSP Cloning Wizard, instead of having us manually copy XML files and hand-install registry files.