WotC has released a preview of the Manual of the Planes:
http://www.wizards.com/default.asp?x=dnd/4ex/20081117a
It has a really cool map of the cosmology, using the Shadowfell and Feywilds as parallel to the mortal world. The Astral Sea and plains have direct links to each of the mortal worlds. The Elemental Chaos is opposite and not connected to the Astral Sea. This is almost exactly how I imagined Athas to exist… and it’s very similar to some of the pictures painted by Athasian sages (reference: Defilers and Preservers – Wizards of Athas).
The changes I’d make are as thus: Add The Grey between the Moral World and the Astral Sea, removing the drawn conduits. Scorch the Feywild to a desert like Athas. Rename the Shadowfell “The Black” and include a “Hallow” region. There are no traditional Wizards, because they’d need to “reach” through the Grey to access the Arcane power source. Instead, Rajaat discovered a way to access Arcane magics from the Feywild. During the cleansing wars, the Feywild was nearly depleted of energy, causing devastation to life on Athas. Similarly, Clerics cannot reach through to the Astral Sea without conduits. Instead, they reach in the opposite direction to the Elemental Chaos. It all makes sense!
Anyways, just jotting down some ideas. No idea how Warlocks would fit into this… unless they can tap into The Black, the Elemental Chaos, or other sources.

Interesting view, BTW I’d change the “scorched” feywild with the NEXUS.

Yup, i’d strongly suggest athas.org look at this doc, looks good to me!

What’s the nexus? I don’t recall that term?
BTW, what was the explanation for the abyss in 2e Darksun? I remember one sorcerer king had door made out of abbyssal steel or something…
I suggest warlocks make pacts with The Gray, The Black, and The Primal Chaos. Do we really need a Feywild in every setting? Elves evolved from halflings, just like everyone else.

The NEXUS is where psionic power comes from. It’s a realm of thoughts and dreams. I don’t want to be too much philosophical but in this cosmology we’d have the two twin planes of Morpheus and Thanatos…

I was just thinking about the amount of 4E material that could be reused for a DS campaign: The Black is similar from how the Shadowfell is described. Actually, there’s another excerpt from WofC on the Shadowfell:
Shadowfell
This article names the Shadowfell as the Domains of Dread… remember Ravenloft (okay, Ravenloft: the domain of the Raven Queen… kind of makes sense). Not exactly how I pictured The Black, but for some DMs, this might be doable. Access to the Domains of Dread is almost identical to gaining access to The Black (by passing through shadows). The dead are sent to the Black, and then ushered to the Astral plan (and the dieties)... but get stuck in the Gray. Both the Black and the Gray houses undead (think Guistenal, Kalid-Ma as a Dread Lord, Bodach or the Dead Lands).
Star Pact Warlocks could use the Black as a power source. Dark Pact Warlocks (Forgotten Realms) could use the Gray as a power source. Neither of these fit perfectly, and I might even reverse the two.
As for the Feywilds… I combed through the DS literature and found some thread-thin references between the Feywilds and the Nexus (cuddos to IL_PROFANATORE for the idea). So here goes:
The Green Age is always described as a world of wild teaming life manipulated by strong psychic energies. The Nature Masters are one example of powerful psionists that manipulated the wilds with the use of their psychic powers. Maybe, during the Green Age, the Feywilds and Athas were really close. The Nature Masters might have used the Feywilds as a power source for their own power.
With the passing of the Green Age, so does access to the Feywilds. Now, access to the Feywilds might be limited to using Green Age artifacts, such as the Pristine Tower or the Tree of Life.
Fey Pact Warlocks would have access to the Feywilds/Nexus as their power source – whether this is simlar to a Psionic, Arcane or other power source I’m not sure. Of course, this class would be much more common during the Green Age and might now be an obselete class.
Some DMs might allow Infernal Pact Warlocks to have access to beings in the Elemenetal chaos (note, the Abyss is a part of the Elemental Chaos) – an idea I find interesting and conceivable.

Excuse the bluntness, but why the sudden excitement at the possibilities of incorporating 4e material (Shadowfell, Feywild) into 4e DS, while people weren’t lining up (and were frankly opposed) to incorporate 3e material (Baator, Bytopia, the Greet Wheel, Sigil) into 3e DS, or incorporating 2e material into 2e DS.

Different people replying to different threads methinks

Purists vs newer posters maybe. A few people seem to be leaning towards a reboot of the world. Alot of 2nd d material sucked.

Bluntness excused. Running 4e DS campaign today is difficult because there’s so little material available. Just wanted to make use of as much of the existing material as possible… but I agree that most of it strikes against some of the purist ideals.

I think it takes a lot less stretching to make DS conform to 4e material when it’s so very open ended. 3e had much cleaner definitions with less room for fudging without upsetting purists.

Heres my work for my 4th ed DS campaign. Its basically been done to incorporate the 4th ed cosmology into DS.
History
The following is an update to the classic timeline.
Creation
Eons ago the gods and primordials went to war for the fate of the universe. After their defeat most surviving primordials fled to the elemental chaos. One however named Athak-Kor had a different idea. Athak-Kor had in his possession an artifact of great power perhaps predating creation itself. Known as the Dark Lens it was likely a tool created by the gods or the greatest of the primordial lords to aid in creation. His goal was to find a hidden refuge form the gods and set it beyond their power. Athak-Kor created his own pocket reality and siphoned material away from planar chaos and created his own elemental planes. He isolated an expanse of the Astral Sea and erected a planar barrier known as the Gray to keep out the vengeful gods. He created a gate capable of piercing the planar barrier and summoned a handful of primordial followers to join him in his exile and appointed them as elemental lords. Finally using the Dark lens and planar gate he engorged his body on elemental matter and took on the shape of a world. Coating himself in a layer of water he used the Dark Lens to separate his essence from his body and then split his essence up into aspects that would later become known as spirits of the land. His body would become known as Athas.
Athas was covered in water and had no sentient native races. One of his aspects millennia later used the planar gate to reach beyond Athas and found some primitive Halflings to populate the islands scattered across the face of Athas. On Athas however a barely sentient race of insects which would later become known as the Kreen had evolved. Eventually the Halflings would create their own civilization and the Kreen reached full sentience as a side effect of an event that would later become known as The Rebirth. Thousands of years would pass and the events on the Kings Age calendar would unfold. Eventually a being known as Dregoth would attempt a ritual that would change the nature of Athas forever.
Dregoth had recovered the ancient gate used by Athak-Kor. Over hundreds of years he used it to visit other worlds. Over the millennia the planar barriers surrounding Athas weakened and a trickle of planar travelers managed to reach Athas and its cosmology. Such travel however was dangerous and often travel to and from Athas was one way. While visiting other worlds Dregoth became obsessed with becoming a true god, not quite realizing that it was impossible on Athas. While his attempt at godhood failed it did dissolve the ancient planar boundaries and return Athas to the material world. However the ancient rituals of binding used to keep out the gods are still intact.

I think if they redo the setting officially in 2010, the new Dark Sun will not only include event pass (revised box) but also be more compatible with the 4E stuff.
Like the planes probably with The Gray barrier explain and all the phb stuff much more compatible. Like for exemple the Dragonborn as the Dray (a 3rd gen?) and many more.

I’ve always viewed the grey as an artificial construct caused by some accident – there are hints it may not have existed in the past, and it is getting thicker. My personal theory is that the grey is the left-over ‘waste’ from a battle between elementals and gods – think of it as smoke left over from an ALMIGHTY spiritual BANG – that ‘smoke’ is deadly to the spiritual energy of mortals and thus sucks souls dry as they fly through it towards the outerplanes, in my own personal cosmological explanation of the grey, in the distant past souls did reach the outer planes, but this became less frequent as the smoke thickened after consuming souls etc etc etc

Or maybe it’s due to Defiling. After all, Athas have the Silt Sea. Maybe the Gray was cause by powerful Defiling spells at the beginning of magic. Maybe the Gray grow as defiling continue to kill Athas?

Anything is possible!