Walking across the wasteland, turn around to discover Charon has disappeared. I figure he'll catch up, so keep going. After about 10 minutes, I get a message telling me he's dead.
Now, I should point out that this is AFTER installing Broken Steel, but BEFORE I began any of the BS quests.
Eventually I get around to doing the BS quests. During the final quest, just as I step off a certain vehicle, in the process entering a previously inaccessible area, guess whose body I find on the floor in front of me...
I'll be honest, I found that both very confusing and yet also pretty hilarious