Laurefindel
Legend
One of the greatest obstacles I see with 5e Dark Sun (which, I believe, is why we haven't seen a DS setting so far) isn't so much about what's missing; it's about all the stuff that doesn't fit-in. Dark Sun, more than any other D&D setting ever published, is defined by what it isn't just as much as what it is.
In every setting and adventure released so far, you can make a character out of the PHB - any character - and there's a place for it somewhere in the world/setting/adventure. Maybe you can't make an Eberron-specific character fit in all D&D settings, but any "vanilla" character can fit in Eberron in one way or another. It's actually one of the setting's call card; "if it exist in D&D, there is a place for it in Eberron".
Not so much in Dark Sun
I never paid attention to 4e Dark Sun, but I wonder what they did with gnome characters. I'm sure they weren't your typical PHB tinker gnome, if they existed at all. But that's what's so attractive and simultaneously off-putting about Dark Sun, nothing is your typical PHB _____. It would almost require a rewrite of the Part I of the PHB, keeping the crunch and replacing all the fluff with Dark Sun goodness.
In every setting and adventure released so far, you can make a character out of the PHB - any character - and there's a place for it somewhere in the world/setting/adventure. Maybe you can't make an Eberron-specific character fit in all D&D settings, but any "vanilla" character can fit in Eberron in one way or another. It's actually one of the setting's call card; "if it exist in D&D, there is a place for it in Eberron".
Not so much in Dark Sun
I never paid attention to 4e Dark Sun, but I wonder what they did with gnome characters. I'm sure they weren't your typical PHB tinker gnome, if they existed at all. But that's what's so attractive and simultaneously off-putting about Dark Sun, nothing is your typical PHB _____. It would almost require a rewrite of the Part I of the PHB, keeping the crunch and replacing all the fluff with Dark Sun goodness.