I'm A Banana
Potassium-Rich
Except the whole "planar isolation of Athas" is hugely overblown, especially in the context of the original setting.
I'm personally less interested in "remaining faithful" then in "being awesome." I don't have much use for historic purity or nostalgia, but awesome in any form is always welcome. The original had indisputable awesome in that brutal world. Isolation enhances that awesome. Low-level 2e didn't have blink elves, after all. And without traditional D&D magic, planehopping player characters weren't much of a concern. If you can run away to a better place by being a 1st level blink elf, it's not much of a Crapsack World, it's just a crapsack neighborhood. Which is nice and evocative, until you move out.
I mean, that's part of why "the gods are silent" has such potency for a player: you are alone, a happy afterlife does not await you, and there is no escape from the brutal world you were born into. That's what motivates you to do Heroic Things like kill sorcerer-kings. The planar isolation goes hand-in-hand with that, I feel.
And, yeah, I'm a little disappointed about how the Feywild is a "magic desert," and the eladrin are basically psionic magicians instead of arcane magicians. For the first, I don't get why magic deserts have to be on an all-new plane (Athas can't have magic deserts without it being the Feywild? Isn't the whole setting basically a giant magical desert? Aren't all those mysterious places he mentioned as inspiration in the real-world deserts?), and for the second, it seems overly cosmetic (I am still a shiny spellcasting teleporting squishy elf, even if my damage + status effects have a slightly different name).
Not that I can't do what I want with the place, of course. And I certainly will, because this is hardly a deal-breaker.

And to that guy at my table who always plays Eladrin, I will say this: "Why do you play eladrin? What's your archetype here? Shiny, aloof, wise, nature-friendly, squishy mage? Try a Noble who is also a Preserver. Nature-mage? Have you given the Primal power-source a look? Wanna be Legolas? Try a standard Elf. Just love the mobility mechanics? I hear Thri-Kreen have an awesome jump ability. Just want the ability scores, act all superior, and hug trees? Heck, use the stats, I'm calling you a 'human,' and we're both happy. You're weird for a human, but whatever. "
I'd rather help them realize how their preferred character elements, whatever they really love about their blink elves, fits into Dark Sun without the need for world elements that I think disrupt the feel, like a Feywild, or a whole race of squishy mages (not arcane mages, but still...).
It's kind of a downer for Dark Sun, but I can presumably ignore it there. It's kind of a bigger downer that even in a world that deliberately and gleefully violates all sorts of standard fantasy tropes, sacrificing sacred fantasy cows like there was a hamburger shortage, the team won't dare to put their own sacred cows on the butchering line. It makes me a little cautious of settings from WotC in general. If everything is just going to essentially look like the PHB with a fresh coat of paint, then it's not really delivering what I, as a voracious consumer of settings, am looking for: a unique play experience. Different adventures to go on. Different kinds of heroes to be. Different realities to understand. Different worlds to explore. If even a world without nature and magic needs a Feywild, for whatever reason (appeasing Eladrin fangirls, ensuring PHB compatibility, or just maintaining Brand Identity across settings), the chances of getting a setting that is compelling and unique enough to demand my attention (and, ultimately, purchase) appears to drop.
At the moment, though, all I can really say is that Rich Baker's post about the Eladrin of Athas sounds like it takes a bit of the awesome of the setting and sells it up the river in an attempt to placate PHB purists. Which is a bit disappointing. Though not the end of the world.