This is probably going to pop up in other places on my flist but because I'm the WDW junkie that I am, I want to say something about it:
MousePlanet blog post about the incident. Link to guest-shot video immediately after the collision. This upsets me SO much. I know exactly where that is, and it was usually the Epcot monorails that we'd ask to ride in the front of. In WDW (never been to DL) you can ride in the front of the monorail with the captain if you ask. The nose is lined with seats for this. We usually asked to ride in the front of the Epcot monorails because it's the longest trip, about 5 minutes. It's a good thing there were no families in the front of purple (since it appears pink was heading for the garage for the night and was out of guest service for the day) or else this could have been even worse.
When we spoke with one of the captains before on one of our rides he told us that every monorail is equipped with radar that detects how close the train is to other monorails on the track. It's why monorails stop in the middle of the tracks sometimes; it senses it's too close to another car. Apparently when monorails are in reverse for track switching at the end of the day, all of their safeguards are disabled.
I feel so bad for the driver's family... he was only 21.