If you want to discuss MMOG and community-game design, I’d strongly suggest you go somewhere like MUD-DEV
http://www.kanga.nu (and look for the MUD-DEV link at the top of the page)
…Bartle is active on the list, as are most of the influential (and experienced) people in the MMOG and commercial MUD industries. But first you should probably read the last 4-5 years of the mailing list, all online and web-browserable by thread/author/etc. Most of the things you can think of have been discussed, analysed, and conclusions (where possible) made. And with a good variety of viewpoints, too.
If you just want a quick look at state-of-the-art in MMOG design and development, take a look at the Agora Twiki:
http://agora.cubik.org/wiki/view/Main/GameDesign
…which accumulates quite a lot of the distilled knowledge of MUD-DEV (although this twiki is young, and probably only covers 0.01% of the material in the MUD-DEV archives). I’ve put that link in the Wiki here (there didn’t seem to be anywhere else for it to go other than the front page…hope that’s OK?).