I took a look at my HP MediaSmart ex470 this morning, and I noticed that the drive lights were all blinking on and off in about a 1 second interval. I was hoping that this wasn't an indication that all 4 drives or the motherboard was dying, and the manual didn't describe an error state that would cause the lights to blink in this pattern.
I then found this page that describes the easter egg that HP put into their software. Somehow, this got enabled on my server. (Maybe this gets enabled on Father's Day.)