At least only the rear brakes failed, so I could come to a crashing halt on the front brakes in time to avoid hitting the bitch on a cell phone standing there staring at me and making no effort to get the fuck out of my way. Apparently, my yelling "oh shit, NO BRAKES" didn't get the idea across.
So I am now without a working bicycle until the weekend, when I'll be able to haul it to the local bike repair shop. It's not too terribly long, but it's still an irritating thing to have happen.