Apparently Wizards of the Coast will revive the Dark Sun property in 2010.
http://www.wizards.com/default.asp?x=dnd/drfe/20090814 I'm
cautiously optimistic. Wyatt's description of the setting sneakily hints that they'll sneak in a few sneaky retcons, perhaps using some method involving sneaking, but that's okay. Most of my pregripes* involve the problems posed by running a deliberately unbalanced setting like Dark Sun within a balance-obsessed system like D&D4e.
For example, defilers in the setting are very deliberately "broken" when compared to other classes. This is not a development oversight or a playtest bug; it's a keystone of the setting. Defiling is the magical equivalent of clear-cut logging combined with toxic waste dumping: It fuels magic by ripping lifeforce from the surrounding area, instantly killing all plants and turning the soil to sterile ash. It's unambiguously horrible and evil... but you get more power, and sooner, than anybody else in the setting. In game mechanical terms, defilers level faster than most other classes, and about twice as fast as non-defiling mages.
If defiling didn't have such a colossal short-term payoff, if it weren't so obviously advantageous, you wouldn't have had the mass-scale defiler warfare that led to Athas becoming a barren wasteland. The official D&D3.5 conversions tried to handle this with special defiler-only metamagic feats, but the need to keep them on an equal footing with every other class meant it just didn't work. This meant the narrative just didn't work. Imagine a post-nuclear-holocaust setting in which fusion bombs weren't a particularly powerful form of warfare. Doesn't make sense, does it? That's Dark Sun without overpowered defilers.
I have some other concerns as well, such as how Dark Sun psionics will work in an edition of D&D that considers psionics to be merely another variety of magic, but overall I'm excited. If you're looking for a solid tabletop wargame with optional roleplaying components, Dark Sun and D&D4e should be a great match.
* Somewhat like "precrime." We raging fanboys can confidently predict suck before it actually happens, unlike poseurs who have to wait for the actual product to determine whether or not it's good.