As far as the feywild goes, Dasuul's concept isn't bad, though I'd hesitate to let PC's be from such a place normally. It's the idea that if it's rare and special and precious, it should probably not be common to the PC party, so that the emotional impact of it can be preserved. If every DS party has someone that's from a rare island of verdant life, it ceases to become something special to the players, which is what you want: the
players to be affected by it.
Making the teleportation psionic may work, too, but it seems like sort of a cop-out. Still, psions and wizards are similar, mechanically, so maybe making eladrin the "psionic race" in the way that they're the "wizard race" now isn't a bad idea.
I do agree with Professor C in that I think that anything an "Athasian feywild" might have would probably just be better
on Athas itself. Athas is already turned up to 11. There's not supposed to be a higher setting. Any higher setting makes Athas not the highest setting anymore, which weakens it.
And I think this encapsulates what I feel about the feywild being normal lush and magical:
I mean, really... If you could naturally shift back and forth between a desolate wasteland, and a lush magical paradise, which would you prefer to live in?
To me, that's a problem. There should be no paradise on Athas save that which you carve out momentarily for yourself or, at high levels, hope to restore to the world. There shouldn't be some nice retirement home in boca raton that you can just BAMF into whenever you want a nice ice tea. The idea of Athas being
inescapable is key to it being brutal and nasty. That's why making it isolated in the multiverse in 2e was so important: there's no getting from here to anywhere else. You're stuck with it. You can't run away from it. You have to make it better.
Now, feywild aside, I suppose I did start off on kind of a negative note, but I've got a lot of hopes & dreams for the setting, too.
I hope they make Dragonborn Cool. I don't hate the DB's as they exist, but I'm not a tremendous fan. They're overtly monstrous, and making them "proud warrior race" doesn't get rid of that for me (plus, the name grates on me). However, I think they should fit well in Dark Sun, and I could see them being truly awesome, either as "tribal lizard people," or as linked to the sorcerer-kings, their creations. Monstrous races fit comfortably in a DS party, and adding some darkness and brutality with the Sorcerer-Kings might be just the injection of bestial fury that the DB need to catch my attention.
I hope they make survival difficult. 4e overlooks bookkeeping like "water and food" for the most part, which is great, but I think DS needs a different approach, where starvation and thirst are real threats, at least at heroic tier. The buzz I've been hearing about making the terrain your enemy sounds great in this regard. I'm looking forward to watching resources slowly dwindle to 0, when they're still a week's march outside of any major settlement, and the tension that creates.
I hope they let everyone dabble in psionics. Not a full multiclass, but a "wild talent" feat that gives an encounter power or something. Some way for everyone to be a little bit psionic.