While this does work, it has the issue of opening a second instance of whatever program you use it for. I'm at work and haven't tested it with XBMC, but I did try it with another program I have here on my desktop at the moment.
This is why I am a proponent of the "Win+1" method (replace 1 with whatever number the program is on your taskbar at the bottom, for me Plex is the first program I have after the Start button). This combo will start up that program and if you hit it while in it it will do one of two things: 1) bring up the taskbar so you can move your mouse around and bring up another program if you want, or 2) if there is a popup like Anti-Virus programs like to do pressing this key again will bring your XBMC or whatever back to the front.