A few quick facts about my Khardtha setting and some thoughts.

Here's a few preliminary "facts" about the setting and some thoughts on how to incorporate (if need be) the story into the 4th Edition rules. Please keep in mind that I was 16/17 and pretty much brand new to gaming when I started creation of the world, and all my work on the world is in the original form, which may be kinda trite.

1. Khardtha was created by Khard, who resembled (while living) a mortal planeswalker akin to the kind detailed in Magic: The Gathering.
I don't feel this has to change, but I don't think I'm going to give this information out as freely as in the past. PCs may never learn this fact.

2. The Gods are all ascended mortals and, as a result, are all closely tied to, and very meddlesome in, the Prime Material Plane.
I think I'm going to push the deities away from mortal affairs some, making them seem more lofty and unreachable than in the past, though they will still work behind the scenes and may even make appearances.
In the past, all the Gods had domains on Khardtha, small pockets where their divine might was absolute. With the newer, condensed cosmology and my decision to make the powers more aloof, I think I will move them out to planes that make more sense for them. (e.g., Karthoth, god of death, would now reside in the Shadowfell)

3. The Gods are not all powerful immortals.
I like this, and I'm going to keep it. Khard himself, wasn't an all-powerful overgod, by any means, and the power he bestowed onto those he ascended is far from the all-encompassing power of Corellon Larethian, Moradin, etc.
Every deity is an ascended mortal, and many still act much as they did in their natural life...no matter how petty that may have been. Also, these gods CAN be killed.

4. 100 years ago, a War of the Schools threatened to destroy magic as we know it.
I love this war now! The original idea behind it was to introduce monsters I had hashed together or found in odd products or odd player-created PC races that made no sense in context or weren't in any TSR/WotC book. The war also explained how various really wacky things could be retconned into the game as far as magics, monsters, etc., all the while producing a viable reason why there were specialist wizards and why they dropped certain schools.

5. Psionics came to Khardtha when the Illithids first brought their city-ships into the world's orbit.
I used to ban psionics from my game because I didn't ever take the time to learn the systems for it. When I finally relented, I decided there had to be a reason for it...that reason was the Mind Flayers.
All over the world, large flying objects, resembling giant slabs of polished marble appeared in the sky, cloaked to the perceptions of all the inhabitants of Khardtha. The longer the slabs, the city-ships of the Illithids, stayed in orbit, and the more psionic energy pouring into the atmosphere, the more some people began to feel something was happening. Latent psions, psychic warriors, and soul knives suddenly discovered powerful abilities within themselves.
Whole communities would sometimes come up missing as if everyone just walked away from what they were doing. Even stranger things began to happen, and those latents who began to control their abilities were finally able to see the ships, but everywhere they turned, they were dismissed by folk who couldn't percieve them.
The ships then "landed", phasing deep into the ground and then unleashing their hordes of Duergar, Svirfneblin, etc. War erupted, but not an open one. Still today, brave heroes push back the tide of those who would consume our very intelligence. This gave me a way to introduce the Mind Flayers and all the races associated with them, as well as psionics. I really like the idea, so I might not alter it. This would have happened thousands of years ago.

6. Almost every place detailed has a real-world or other-game counterpart.
I'm definitely going to change this. While it worked for a high school student who also had a job and wasn't too keen on wracking his brain to come up with unique cultures, etc., this doesn't work for the gamer I have become and while I might steal from certain cultures, no doubt, I want as little as possible to be recognizable immediately as something from X or Y.

7. The concepts of law and order are upheld almost everywhere, for the most part, by churches, law officials, and powerful companies of ex-adventurers.
I don't like this anymore. I didn't really like it when I made the rule, but my players complained alot of never having a bit of peace, even in the most well established cities with large forces of town guards. I relented then, to keep my players, but now it just leaves a bitter taste.
One of the first things I thought was cool about 4E was the concept of "Points of Light" that the designers had latched onto for civilization. This feel...this world where an oppressive "darkness" waits just on the edge of a tenuous law held within eyeshot of the settlements, maybe a little further, brings a feel to the game that I have wanted.
Furthermore, I want to incorporate more corruption into civil and ecclesiastic orders, and there really shouldn't be Sir Beatum Uppus, Ftr 15, around to steal the spotlight from the PCs.

8. The big guns: Dinosaurs/Prehistoric Creatures.
Yeah! In my original notes, Khardtha, having been spontaenously created and populated through magic, never suffered an Ice Age or anything and is inhabited by both Wooly Mammoths, etc. and Stegosaurs and their scaly kin. Prehistoric creatures have always been something I have been fascinated with and there was no way I could leave them out. This one's staying.
That's right, Eberron, it was my idea first!

So yeah...I'm way sleepy, and this stuff just was coming out. The last point isn't even a big one, but it kicks ass.
More on all this Khardtha/4E garbage to come!