A note regarding "world turned to 11" and all that:
Anything and, indeed, everything that would exist in the Athasian Feywilde should exist in Athas itself instead.
There shouldn't be someplace worse, because Athas is already supposed to be "Deathplanet."
Whenever people say "Well, how about this idea for what the Feywilde is like..." my first thought is "Why not just have that in Athas proper and not shunt good ideas to the other planes?
What's the difference between a terrible environment being directly on Athas vs being on the Athasian Feywild, which exists as scattered pockets throughout the world?
It sounds as though, by this argument, you would be perfectly happy with the same exact scenario, as long as they said, "The feywild isn't a plane anymore, just a bunch of mirages in the desert." Functionally, it is the same thing. The complaint, here, seems almost entirely grounded in abstract theoreticals rather than any genuine impact on how people will be playing the game.
Look, I can accept reasons for not liking the idea of a Feywild in Athas - it sounds like a large part of the complaint is from those who want the threat of the desert to be purely natural, rather than having even worse magical desert threats. And that's fine.
What I don't get is the unwillingness to even acknowledge that others can find those magical desert threats fascinating, and even find them something that enhances the game. This insistence that the only reason the Feywild is showing up in Dark Sun is because the designers insist on shoving in all 4E elements, or because 4E fans need excuses to not think outside the box, or for any number of other reasons, all of which, frankly, are somewhat insulting to the people on the other side of the argument. (I'm particularly disappointed in Wik, here, since I gave him xp earlier in the thread before his posts deteriorated into this sort of activity.)
Redesigning Dark Sun as a 4E setting that is accessible to 4E fans while retaining the flavor of the original setting is exactly what I am looking for. And I can totally understand if that isn't true for others, who truly wanted a perfect remake of the original setting. But you need to accept that there are people who want what WotC is doing now, and not out of blind loyalty or a need to always play Eladrin, but because we genuinely feel that the setting they are producing will be exciting to play in, and that the very elements you dislike will only enhance the brutality of the setting in our games.