I can't take credit for the idea... I saw a similar setup about 8 years ago. I had a spare fridge and was just getting into homebewing, it was a no brainer actually.
At the current time I only have two kegs running. One is a copper ale with a small ammount of apricot extract that barely shows up in the aftertaste. The other is a really dark Brown Ale originally targeted to be close to Moose Drool by Big Sky Brewing Co in Montana, but it went darker and stronger than the drool. It rotates all the time though, I'll probably get another batch going in a few weeks. I haven't really decided what I'm doing next.
Steve- none of this hard. Once you learn the general procedure it's very easy.