Ah, there's a free viewer here.

Googling suggests that it's the native format of a program called Cadence Allegro PCB. Looks like some other software can import .BRD files, too.

Cool! How long ago did you place your order? Just wondering whereabouts I might be in the queue.

Ah, great news. I'm looking forward to receiving mine. A couple of weeks ago I set up a Linux VM and messed around with the cross-compiler package from Marvell's site, and didn't have much trouble compiling rtorrent for the SheevaPlug.

I brought up the topic of this device at work, and you know what everyone immediately thought this thing would be used for? Corporate espionage.