Random generators are useful to have for DMs. Here are a handful from around the web that are specific for Dark Sun.
Dark Sun Random Generators Athasian Name Generator Rhul-Thaun Name Generator Thri-Kreen Random Name Generator Random NPC Random Castle Random Storyhook Random Settlement Random Village Name Generator
Neuroglyph games has posted an interesting 4e encounter featuring a couple of customized undead critters. Designed as a mid-heroic tier encounter, it makes good use of Gray-based (as opposed to your standard) undead.
I like the idea of posting explicit packaged encounters for Dark Sun, and if anybody knows of any other encounters like this, please send me an email.
A new website has been added in the Links section, Athas Reborn, a mod for Neverwinter Nights.