No, it has nothing to do with the Weird West. The official Dark Sun website, Athas.org, has posted a 70 page free PDF called Terrors of the Dead Lands. The supplement describes the undead of Athas, old and new, in preparation for the upcoming supplement Secrets of the Dead Lands. We’ll let you know when the next supplement is posted. In the meantime, I’ll reassert my opinion that undead + psionics = really scary.