Greg spoke at GenCon at the GW panel and talked a lot about how he ran the game and how it played. He just posted his blog on GW, which includes random "background" tables which gave all the PCs something to in his story. Once they all had -- usually mutually exclusive goals -- he could just point them in a general direction and let them all play against each other.
You can check out his blog here
And for those of you who have not seen it, the GW panel from GenCon starts here with part 1 of 3