He started out by saying which MUDs influenced the developers of which early MMOs. For example, LP MUDs had an impact on Ultima Online. Then he named a handful of the best innovations of the modern MMO -- "advanced raiding," instances, improvements to combat via spaciality, etc. After saying all those positive things though, he dropped a bit of a bomb, saying that despite all that, "MMOs have removed more features from MUD gameplay than they have added, when you look at the games in aggregate."
Oh noes! Are the Warhammer Online fans fuming yet? Well, they shouldn't be. "Failure to evolve more radically isn't a flaw," said Koster. He finished up by positing that all the current MMOs "are already Old Guard," and that "the mudder crew is already the Older Guard. So in a sense this is kind of like an argument between art rockers and disco musicians."