There is a very long and comprehensive interview of Richard Bartle on the Guardian games blog, which addresses lots of different topics. Some excerpts I found interesting:

"MUD has little that today's virtual worlds don't, but it lacks something they do have which makes it worth looking at: baggage. In today's virtual worlds, there are many components that are only there because they were in the worlds that the designers played. These things work, but the designers don't know - or even consider - why they work. A designer will ask "what character classes are we going to have?" when they should first ask "are we going to have character classes?". Only when they have decided that yes, they are going to have them, will they know why they want them, and therefore why they are important. With MUD, we had no precedents. Therefore, a designer looking at MUD can do so in the knowledge that everything there is there for a reason, and then hypothesise what that reason might be (or, if they realise I'm not dead yet, ask me). (...) Most people will use the technology but not care about the worlds as worlds. If you want the intelligent stuff, you'll be able to find it; however, if you don't know it's there, you won't know to look."

Why do I blog this? some good points here, also considering what I just blogged about "design inheritance" and the persistence of stereotypes. It's indeed important to see how the game design/user interface/user experience evolved over time from tabletop role-playing games to MUD and them MMORPGs. The strong typologies of "class" or material prevails in an unbelievable way, promoting certain aspects of the games. What would be the alternatives?