I have added an Adobe Atmosphere World to my site. Check it out here. I hope to publish items to it and also add avatars and other goodness in there as an ongoing project. So far there is not much there but in the future I'll be adding fish, space ships, and other cool stuff.
I also found a really interesting article on the creation of Multiplayer games at ArenaNet. If you like in-depth articles for anything game related then also check out Gamasutra.